Camera: Avoid dequeue too many buffers from buffer queue

The PreviewFrameSpacer could defer 1 or 2 buffers to reduce jitter.
And we update the handout buffer count at the time of queuing to
the preview frame spacer, not at the time of queuing to the buffer
queue.

This results in accounting mismatch where the framework could allow
the HAL to dequeue more buffers than supported.

The fix is to track the framework cached buffer count in addition to the
handout buffer count.

Test: Camera CTS, vendor testing, observe logcat with GoogleCamera
Bug: 242674531
Change-Id: I579ae7465b59f5bd9e12dfda332998b401793eb4