Initial commit for media apex bundle

The dependency clean up hasn't finished yet. The private API usages
will be replaced with stable APIs gradually.

This is not built by default when building the system image.

Test: make apex.media; make; flash; adb shell ls /apex/
Bug: 112766913
Change-Id: I56e59b2492c09bf315e24180f8b04f1f24d32e2d