BufferQueue: Fix deadlock in setMaxAcquiredBufferCount

Uncovered this while testing. The deadlock happens when:

- ConsumerBase::setMaxAcquiredBufferCount locks itself
- Calls IGBC::setMaxAcquiredBufferCount, which can call
  ConsumerListener::onBuffersReleased
- Which, in ConsumerBase, will take the lock again

Instead of this, we add a callback to be called instead of the
IConsumerListener. This callback is called on the same stack, with the
lock held, so that we can resolve everything atomically.

Bug: b/393639203
Flag: EXEMPT small cleanup
Test: new test
Change-Id: Iddd8f902d1fd0aeed6aac095eaa6c0b870ffff70