Stabilise flaky test by waiting for binder calls to be complete

The test is flaky with the error that play/pause button is not visible.
Add wait for binder calls to be completed and device to be idle.

Bug: 232183099
Bug: 232046773
Bug: 232340721
Test: atest PhotoPickerTest --iterations 20
Change-Id: Ic63377f491c8922fab6e37191f028672027e68a7
Merged-In: Ic63377f491c8922fab6e37191f028672027e68a7
(cherry picked from commit 7ba5cafdb8944d14e3aa0ff8554e703365444022)
1 file changed