libaudioclient: Align test execution tracing

Extract TestExecutionTracer helper and use it in all unit
tests.

Bug: 318423731
Test: m audiorecord_tests audiotrack_tests audioeffect_tests \
        audioeffect_analysis audiorouting_tests \
        audioclient_serialization_tests trackplayerbase_tests \
        audiosystem_tests
Change-Id: Ib588e560f5993e86689ac8fe65e129a967ecf874