Minor Autofill javadoc fixes.

 * <pre class="prettyprint">

 * private static String getCanonicalDomain(String domain) {

 *   InternetDomainName idn = InternetDomainName.from(domain);

 *   while (!idn.isTopPrivateDomain() && idn != null) {

 *   while (idn != null && !idn.isTopPrivateDomain()) {

 *     idn = idn.parent();

 *   }

 *   return idn == null ? null : idn.toString();

 * </pre>

 *

 * <p>If the association between the web domain and app package cannot be verified through the steps

 * above, the service can still autofill the app, but it should warn the user about the potential

 * data leakage first, and askfor the user to confirm. For example, the service could:

 * above, but the service thinks that it is appropriate to fill persisted credentials that are

 * stored for the web domain, the service should warn the user about the potential data

 * leakage first, and ask for the user to confirm. For example, the service could:

 *

 * <ol>

 *   <li>Create a dataset that requires

 *   <li>Include the web domain in the custom presentation for the

 *       {@link Dataset.Builder#setValue(AutofillId, AutofillValue, android.widget.RemoteViews)

 *       dataset value}.

 *   <li>When the user select that dataset, show a disclaimer dialog explaining that the app is

 *   <li>When the user selects that dataset, show a disclaimer dialog explaining that the app is

 *       requesting credentials for a web domain, but the service could not verify if the app owns

 *       that domain. If the user agrees, then the service can unlock the dataset.

 *   <li>Similarly, when adding a {@link SaveInfo} object for the request, the service should

 *

 * <p>This same procedure could also be used when the autofillable data is contained inside an

 * {@code IFRAME}, in which case the WebView generates a new autofill context when a node inside

 * the {@code IFRAME} is focused, which the root node containing the {@code IFRAME}'s {@code src}

 * the {@code IFRAME} is focused, with the root node containing the {@code IFRAME}'s {@code src}

 * attribute on {@link android.app.assist.AssistStructure.ViewNode#getWebDomain()}. A typical and

 * legitimate use case for this scenario is a financial app that allows the user

 * to login on different bank accounts. For example, a financial app {@code my_financial_app} could