Introduce a new flag to enable crashing the app on FGS timeout.

Decouple what happens to an app after one of its foreground services
times out. With this new flag enabled, instead of ANRing the app, crash
the app.

Bug: 339526947
Test: atest CtsFgsTimeoutTestCases
Flag: android.app.enable_fgs_timeout_crash_behavior
Change-Id: I8270f50294af17d8bff1ab00ddb33b88d0a68283