blast: Add composer overlay flag to AHardwareBuffer

BLAST allows apps to directly allocate their buffers instead of
going through BufferQueue. BufferQueue typically adds this flag for the
apps. Now apps need the ability to add the flag to the buffer themselves.

Test: atest CtsViewTestCases:android.view.cts.ASurfaceControlTest
Bug: 80477568

Change-Id: Ife4b9b7cea39bf5f852b51cb918737e79fe2029e