Replace flag rule with flag annotations

Flag rule based calls happen exactly when they're made, and allow for
setup code to be ran without the properly set flag values. This is
errorprone and can cause subtle bugs where the flag values don't appear
to be set properly.

Instead, we should use the new annotations, which are executed _before_
setup is called.

Bug: 352982293
Flag: EXEMPT, test only change
Test: atest BrowseTreeTest.java
Test: atest AvrcpControllerServiceTest.java
Test: atest AvrcpControllerStateMachineTest.java
Change-Id: Iff1c55f96b51269bbc74492d464135e7cc579744