java/com/android/incallui/res/layout/activity_manage_conference.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/manageConferencePanel"
  android:layout_width="match_parent"
  android:layout_height="match_parent">
</FrameLayout>