Skip test if chosen effect is not available on device

Also update getEffectDescriptor test for null args

Bug: 215781480
Test: atest audioeffect_tests

Merged-In: Ibc4ce76afac889ed6c95e7b028db4cf7b395e04d
Change-Id: Ibc4ce76afac889ed6c95e7b028db4cf7b395e04d
1 file changed