BroadcastQueue: ignore racing finish messages.

Since moving to enqueueFinishReceiver(), we've noticed an uptick in
our checkState() failing.  Our current hunch is that we're racing
with the remote app thread, but further investigation is needed.

Reduce this check to a log message for the moment to keep dogfooding
metrics clean.

Bug: 256999794
Test: atest FrameworksMockingServicesTests:BroadcastRecordTest
Test: atest FrameworksMockingServicesTests:BroadcastQueueTest
Test: atest FrameworksMockingServicesTests:BroadcastQueueModernImplTest
Change-Id: I90acd7ebbea0a7a8ab89db8f3c7463f9a9a909c7