Fix stale buffer release issue.

BufferItemConsumer sometimes returns BufferItems where mIsStale is already set to true, breaking the logic for ignoring buffers that were released via a disconnect. This CL adds a new field for BLAST to use for this purpose.

Bug: 294133380
Flag: com.android.graphics.libgui.flags.buffer_release_channel
Test: CtsMediaDecoderTestCases, CtsDeqpTestCases
Change-Id: Ie32c9c6e0e26e68b794a1ca78cdd3c2395ac0966