AudioFlinger, AudioPolicy: Add binder time check statistics

Binder method count and execution time now in dumpsys.
Add method name to TimeCheck abort logs.
Add MethodStatistics utility class to accumulate values.

Test: atest libmediautils_test
Test: atest method_statistics
Test: atest timecheck_tests
Test: adb shell dumpsys media.audio_flinger
Test: adb shell dumpsys media.audio_policy
Test: adb shell dumpsys media.metrics
Bug: 219958414
Change-Id: I7398d706e475596af6ad491463e87e92b09026d8