Support and document the availableCameras property in Ti.Media.

TIMOB-12970
Merge remote-tracking branch 'upstream/master' into timob-12970

Conflicts:
	android/runtime/v8/AndroidManifest.xml
Remove unneeded "since" yaml keys for ipad/iphone

The "since" key for ipad/iphone in Media.yml availableCameras, CAMERA_FRONT
and CAMERA_REAR entries were not needed because they've been there
for some time though undocumented.
TIMOB-12970
Merge remote-tracking branch 'upstream/master' into timob-12970
Remove ipad/iphone from "since" for
availableCameras

TIMOB-12970
Merge pull request #4450 from billdawson/timob-12970

TIMOB-12970 Android: Support and document the availableCameras property in Ti.Media.