Remove flag powerhint_thread_cleanup & cpu_headroom_affinity_check

Bug: 400533784
Bug: 409610751
Flag: EXEMPT removing powerhint_thread_cleanup cpu_headroom_affinity_check
Test: atest HintManagerServiceTest PerformanceHintManagerStatsTests
Change-Id: I0db3b6f243c0ff6df1947990f13a1d6a2ad8a2c9
3 files changed