Use AlertDialog for MediaRouteControllerDialog

import com.android.internal.R;

import android.app.Dialog;

import android.app.AlertDialog;

import android.app.MediaRouteActionProvider;

import android.app.MediaRouteButton;

import android.content.Context;

 *

 * TODO: Move this back into the API, as in the support library media router.

 */

public class MediaRouteControllerDialog extends Dialog {

public class MediaRouteControllerDialog extends AlertDialog {

    // Time to wait before updating the volume when the user lets go of the seek bar

    // to allow the route provider time to propagate the change and publish a new

    // route descriptor.

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        getWindow().requestFeature(Window.FEATURE_LEFT_ICON);

        setContentView(R.layout.media_route_controller_dialog);

        mVolumeLayout = (LinearLayout)findViewById(R.id.media_route_volume_layout);