Public Audio playback capture must have a valid projection

For privacy, require the app wanting to capture other app audio to have
a valid MediaProjection.

Test: adb shell audiorecorder --target /data/file.raw
Bug: 111453086
Change-Id: I1323048fe308282d3719e38915818a0da17567de
Signed-off-by: Kevin Rocard <krocard@google.com>
8 files changed