Add hexadecimal toString for AudioUuid

Bug: 283012471
Test: atest audio_aidl_utils_test
Test: Flash to Pixel phone and check log
Change-Id: I0a2971bdd771cae276a55dec335cd033ab414f64
Merged-In: I0a2971bdd771cae276a55dec335cd033ab414f64
3 files changed