SoundPool: Fix clang-tidy

Test: touch *.cpp,  mma, verify no clang-tidy warnings
Test: SoundPoolAacTest, SoundPoolHapticTest,
Test: SoundPoolMidiTest, SoundPoolOggTest
Bug: 182414042
Change-Id: I77af4f0999c46931d6993d917443df1fa8425353
4 files changed