Apps and system_server are gralloc HAL clients

This commit marks system_server and app domains (except isolated_app)
as clients of Graphics Allocator HAL. This makes the policy cleaner
and prepares ground for restricting access to HwBinder services.

Test: Play video in YouTube app and in Google Chrome YouTube web page
Test: Using Google Camera app, take an HDR+ photo, a conventional
      photo, record a video with sound and a slow motion video with
      sound, then check that photos look good and videos play back
      fine, including sound.
Bug: 34454312
Change-Id: Iea04d38fa5520432f06af94570fa6ce16ed7979a