aaudio: handle DSP stalls in clock model

The DSP can sometimes stall while playing.
This might happen when switching internal routes.
That can cause a large jump forward in the timestamps
passed to the IsochronousCLockModel.

When that happens we need to immediately move
the window of the clock model forward and let it
recalibrate using early timestamps.

Otherwise we can end up with the DSP in the middle of the buffer
and a clock model that is drifting too slowly towards
a correct timing window.
That can result in buzzing and clicks depending on the BufferSize.

Also fix test_clock_model.cpp
Added better simulation of timestamp jitter.
Look for position in a range.
Drift more slowly.
Simulate a pause in the DSP.

Bug: 264949085
Bug: 214121016
Bug: 200134791
Test: See bug for repro steps
Test: atest AAudioTests
Test: atest test_clock_model
Change-Id: I9edf4d71ca99ef5827c3c368603a96c52491aad6