[Audiosharing] Use DialogFragment instead of raw AlertDialog

FragmentManager can help manage the state of the dialog and automatically restore the dialog when a configuration change occurs

Test: atest
Flag: com.android.settingslib.flags.enable_le_audio_sharing
Bug: 362858921
Change-Id: If63c7891cfb92e06c457e37eb5556f3eaf3f6121

src/com/android/settings/connecteddevice/audiosharing/AudioSharingProgressDialogFragment.java

@@ -80,6 +80,7 @@ public class AudioSharingProgressDialogFragment extends InstrumentedDialogFragme
                 if (messageView != null) {
                     messageView.setText(message);
                 }
+                sMessage = message;
             }
             Log.d(TAG, "Dialog is showing, return.");
             return;