Allow apps to create FGS with type mediaProjection if the user granted

...the media projection permission from the system dialog
(i.e. MediaProjectionPermissionActivity).

The updated flow of starting a media projection will be:

1. Declares a FGS with type mediaProjection
2. startActivityForResult(MediaProjectionManager#createScreenCaptureIntent())
3. [NEW] Start the FGS on getting the result from step #2
4. MediaProjectionManager#getMediaProjection()
5. MediaProjection#createVirtualDisplay()

Also, bring back the permission enforcement for mediaProjection FGS
which was removed in I1efa698207182043cfab3d5503829da8eec075ab.

Additional, this CL added the feature flags for the permission
enforcement for each FGS type.

Bug: 267740338
Bug: 246792057
Test: atest CtsMediaProjectionTestCases
Test: atest CtsWindowManagerDeviceTestCases
Test: atest CtsAppFgsTestCases
Change-Id: I1e5b58ddea232fecaaa5ed513276a62c72429a0b
Merged-In: I1e5b58ddea232fecaaa5ed513276a62c72429a0b