Fix WaveGenerator memory leak

Releasing memory with ToneGenerator::stopTone() depends on
ToneGenerator::mState that can cause memory leak in case
mState is TONE_INIT.

Remove dependency to mState by adding ToneGenerator::clearWaveGens()
explicit call in ToneGenerator destructor.

Bug: 29916937

Change-Id: I5ccfbca9f2ae1abac9e160a2a309fb6962d4a110
1 file changed