minor improvements for VtsHalAudioEffectFactoryTargetTest

Bug: 327678656
Test: atest VtsHalAudioEffectFactoryTargetTest
Change-Id: I95f19d20883142cd500c552966bd8f02256a1be5
Merged-In: I95f19d20883142cd500c552966bd8f02256a1be5
1 file changed