Fix contentprovider docs android:exported default

<dl class="xml">

<dt>syntax:</dt>

<dd><pre class="stx">&lt;provider android:<a href="#auth">authorities</a>="<i>list</i>"

<dd>

<pre class="stx">

&lt;provider android:<a href="#auth">authorities</a>="<i>list</i>"

          android:<a href="#enabled">enabled</a>=["true" | "false"]

          android:<a href="#exported">exported</a>=["true" | "false"]

          android:<a href="#gprmsn">grantUriPermissions</a>=["true" | "false"]

          android:<a href="#sync">syncable</a>=["true" | "false"]

          android:<a href="#wprmsn">writePermission</a>="<i>string</i>" &gt;

    . . .

&lt;/provider&gt;</pre></dd>

&lt;/provider&gt;</pre>

</dd>

<dt>contained in:</dt>

<dd><code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code></dd>

<dd>

    <code><a href="{@docRoot}guide/topics/manifest/application-element.html">&lt;application&gt;</a></code>

</dd>

<dt>can contain:</dt>

<dd><code><a href="{@docRoot}guide/topics/manifest/meta-data-element.html">&lt;meta-data&gt;</a></code>

<br/><code><a href="{@docRoot}guide/topics/manifest/path-permission-element.html">&lt;path-permission&gt;</a></code></dd>

<dt>description:</dt>

<dd>Declares a content provider &mdash; a subclass of 

{@link android.content.ContentProvider} — that supplies structured 

access to data managed by the application.  All content providers that 

are part of the application must be represented by {@code <provider>} 

elements in the manifest file.  The system cannot see, and therefore will 

not run, any that are not declared.  (You need to declare only 

those content providers that you develop as part of your application,

not those developed by others that your application uses.)

<dd>

    Declares a content provider component. A content provider is a subclass of 

    {@link android.content.ContentProvider} that supplies structured access to data managed by the 

    application.  All content providers in your application must be defined in a 

    {@code <provider>} element in the manifest file; otherwise, the system is unaware of them 

    and doesn't run them.

    <p>

The Android system identifies content providers by the authority part

 of a {@code content:} URI.  For example, suppose that the following URI 

is passed to <code>{@link android.content.ContentResolver#query 

ContentResolver.query()}</code>:

<p style="margin-left: 2em">{@code content://com.example.project.healthcareprovider/nurses/rn}</p>

        You only declare content providers that are part of your application. Content providers in

        other applications that you use in your application should not be declared.

    </p>  

    <p>

The {@code content:} scheme identifies the data as belonging to a content 

provider and the authority ({@code com.example.project.healthcareprovider}) 

identifies the particular provider.  The authority therefore must be unique.  

Typically, as in this example, it's the fully qualified name of a 

ContentProvider subclass.  The path part of a URI may be used by a content 

provider to identify particular data subsets, but those paths are not

declared in the manifest.

        The Android system stores references to content providers according to an <b>authority</b>

        string, part of the provider's <b>content URI</b>. For example, suppose you want to 

        access a content provider that stores information about health care professionals. To do

        this, you call the method 

        {@link android.content.ContentResolver#query ContentResolver.query()}, which among other

        arguments takes a URI that identifies the provider:

    </p> 

<pre>

content://com.example.project.healthcareprovider/nurses/rn

</pre>

    <p>

For information on using and developing content providers, see a separate document, 

        The <code>content:</code> <b>scheme</b> identifies the URI as a content URI pointing to

        an Android content provider. The authority 

        <code>com.example.project.healthcareprovider</code> identifies the provider itself; the

        Android system looks up the authority in its list of known providers and their authorities. 

        The substring <code>nurses/rn</code> is a <b>path</b>, which the content provider can use 

        to identify subsets of the provider data.

    </p>

    <p>

        Notice that when you define your provider in the <code>&lt;provider&gt;</code> element, you 

        don't include the scheme or the path in the <code>android:name</code> argument, only the

        authority.    

    </p>

    <p>

        For information on using and developing content providers, see the API Guide, 

        <a href="{@docRoot}guide/topics/providers/content-providers.html">Content Providers</a>.

</p></dd>

    </p>

</dd>

<dt>attributes:</dt>

<dd><dl class="attr">

<dd>

    <dl class="attr">

        <dt><a name="auth"></a>{@code android:authorities}</dt>

<dd>A list of one or more URI authorities that identify data under the purview 

of the content provider.

        <dd>

        A list of one or more URI authorities that identify data offered by the content provider.

        Multiple authorities are listed by separating their names with a semicolon. 

        To avoid conflicts, authority names should use a Java-style naming convention 

        (such as {@code com.example.provider.cartoonprovider}).  Typically, it's the name

of the ContentProvider subclass.

        of the {@link android.content.ContentProvider} subclass that implements the provider

        <p>

            There is no default.  At least one authority must be specified.

</p></dd>

        </p>

        </dd>

        <dt><a name="enabled"></a>{@code android:enabled}</dt>

        <dd>Whether or not the content provider can be instantiated by the system &mdash; 

</p></dd>

<dt><a name="exported"></a>{@code android:exported}</dt>

<dd>Whether or not the content provider can be used by components of other 

applications — "{@code true}" if it can be, and "{@code false}" if not.  

If "{@code false}", the provider is available only to components of the 

same application or applications with the same user ID.  The default value

is "{@code true}" for applications which target API level 16 (Jelly Bean)

and below, and "{@code false}" otherwise.

<dd>

    Whether the content provider is available for other applications to use:

    <ul> 

        <li>

            <code>true</code>: The provider is available to other applications. Any application can

            use the provider's content URI to access it, subject to the permissions specified for

            the provider.

        </li>

        <li>

            <code>false</code>: The provider is not available to other applications. Set 

            <code>android:exported="false"</code> to limit access to the provider to your

            applications. Only applications that have the same user ID (UID) as the provider will

            have access to it.

        </li>

    </ul>

    <p>

You can export a content provider but still limit access to it with the

<code><a href="{@docRoot}guide/topics/manifest/provider-element.html#prmsn">permission</a></code> attribute.

</p></dd> 

        The default value is <code>"true"</code> for applications that set either 

<code><a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min">android:minSdkVersion</a></code>

        or 

<code><a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">android:targetSdkVersion</a></code> to 

        <code>"16"</code> or lower. For applications that

        set either of these attributes to <code>"17"</code> or higher, the default is 

        <code>"false"</code>.

    </p>

    <p>

        You can set <code>android:exported="false"</code> and still limit access to your

        provider by setting permissions with the 

   <code><a href="{@docRoot}guide/topics/manifest/provider-element.html#prmsn">permission</a></code>

        attribute.

    </p>

</dd> 

<dt><a name="gprmsn"></a>{@code android:grantUriPermissions}</dt>

<dd>Whether or not those who ordinarily would not have permission to