C2 VTS: Cleanup code around query() calls

- Cleaned up the code that was reading parameters returned in query()
- Ensure both return value and size of parameter vector are valid
- Use ASSERT_EQ() instead of if () checks after query()

Also added a missing ASSERT for verifying number of channels in gsm
decoder tests

Bug: 200329093
Test: atest VtsHalMediaC2V1_0TargetAudioDecTest \
 VtsHalMediaC2V1_0TargetAudioEncTest \
 VtsHalMediaC2V1_0TargetVideoDecTest \
 VtsHalMediaC2V1_0TargetVideoEncTest \
 VtsHalMediaC2V1_0TargetComponentTest \
 VtsHalMediaC2V1_0TargetMasterTest

Change-Id: I3a910fcea6927f1ed48d2457d333a8bc92ee1dcf
Merged-In: I3a910fcea6927f1ed48d2457d333a8bc92ee1dcf