docs: update auth doc to mention multiple scopes bug 7644251

</pre>

<h2 id="obtain">Obtaining an Access Token</h2>

<p>

  With an email address, you can now obtain an access token. There are two general

  With an email address and the service scope you can now obtain an access token.

</p>

<p class="note"><strong>Note:</strong> Specify <code>"oauth2:<em>scope</em>"</code> for a single scope or

  <code>"oauth2:<em>scope1</em> <em>scope2</em> <em>scope3</em>"</code> for multiple scopes.</p>

There are two general

  ways to get a token:</p>

    <ul>

    <h3>Using getToken()</h3>

    The following code snippet obtains an access token with an email address, the scope that you want to use for the service, and a {@link android.content.Context}:

<pre>

HelloActivity mActivity;

String mEmail;