Implement issue #6680894: Provide a way to configure app defaults...

...for a smoother OOB experience

Way provided.

Put your defaults in system/etc/preferred-apps/*.xml.

Figure out what to put there with "adb shell dumpsys package preferred-xml".

Bug: 6680894
Change-Id: Ia06bb0061876274a5f80bf06d1ba5ad155edc323