Update language in AppStateTracker to be more inclusive

Changes to comply with Android's inclusive language guidance.
See https://source.android.com/setup/contribute/respectful-code for
reference.

Test: make -j
atest FrameworksMockingServicesTests:com.android.server

Bug: 162432774
Bug: 161896447
Change-Id: I2f3b5cb6b0e2cfaf9136bf7c9d0b1f5f1f76b612