Remove verification of native method in InCallTonePlayerTest.

Remove verification of ToneGenerator#release(); its a native method and
apparently mockito has issues with this in some cases.  Local runs are
all fine, but apparently Cuttlefish is not.

Fixes: 231726501
Test: Run unit tests and presubmit.
Change-Id: I337df13987f2738a08b36aa12de4e8682535ab49