Camera: Consider the currently acquired input buffers

The maximum acquired count of the input buffer queue during surface
sharing should be set considering the total maximum acquired count of
individual registered outputs and also the current acquired count
of the input buffer queue. The reason the two can be different is
due to the fact that individual outputs can acquire and also block
buffers from the input. The latter portion contains all buffers
which are still queued but not acquired. This can happen in case
some output acquires the maximum amount of buffers possible then
stops consuming entirely and the camera client continues to reference
it in subsequent capture requests.
To handle this, track the number of acquired buffers in the input
queue and expand (or contract) the maximum acquired count only if
possible. The maximum shouldn't change otherwise because the blocked
buffers could still be used by the unresponsive output at some
later point in time.

Bug: 117982710
Test: Camera CTS
Change-Id: Ia4e743efdf59cb0c9baaea492f78c37d0f2c95b3