Introduce BinderSpamSignalCollector

Also moved signal collector service related code to its own directory
with a sparate build target to put it under the same build flag as the
anomaly detector service.

Bug: 419590607
Flag: android.os.profiling.anomaly.flags.anomaly_detector_core
Test: atest FrameworksServicesTests
Change-Id: I08c29b5e6da71f44b5bc8784d127d5d3f47c3430