Track BBQ dequeue count and mode

Counts, shared buffer mode, and async mode will be used to determine when dequeueBuffer should block.

Bug: 294133380
Flag: com.android.graphics.libgui.flags.buffer_release_channel
Test: BLASTBufferQueueTest
Change-Id: I23cd5606f84ac5e0c29c470d05b28153fc4c9ce8