Adds a timeout to monitor where an UncertainTracker is never removed.

The tracker should be removed when a transition reports finish or its
start transaction has been applied. If neither event occurs, the
transition handler may have entered a weird state. This timeout acts as
a safeguard to forcibly remove the tracker and prevent potential leaks.

Bug: 431189806
Flag: EXEMPT bugfix
Test: atest StartingWindowControllerTests
Change-Id: I49a757b37c1500d59e2e2c49d66aca261364c905