Audio policy: fix input preemption logic

Fix the input preemption logic in AudioPolicyManager::getInputForDevice
when the maximum number of opened input stream is reached:
- avoid preemption loops between two AudioRecord clients
- avoid cases were no preemption occurs but an attempt is made to open a
  new input anyway.

The new logic is:
1) reuse an input if the new client has the same session as an existing
   client on this input
2) try to close/preempt an input if possible and then reuse an input
3) the candidate inputs for preemption are inputs with strictly lower
   priority use cases than the new client, or same priority that were not opened
   thanks to preemption or have been active since, ordered by use case priority
   and favoring idle inputs as second criteria
4) if no candidates for preemption are found, reuse preferably inputs
   with the same use case as the new client and favoring active inputs
   as second criteria.

Bug: 338446410
Test: atest audiopolicy_tests:AudioPolicyManagerInputPreemptionTest
Flag: com.android.media.audioserver.fix_input_sharing_logic
Change-Id: I82a953edcf1b3ea76a44ae0d02c943daaacfea64