Stop updating BT devices event history if user is categorized

Once the user is categorized as one of the interested group, there's no
need to update and maintain the event history. Clear the history and
stop monitoring the new events if user is already categorized.

Bug: 294627726
Test: atest CachedBluetoothDeviceTest
Test: atest HearingAidStatsLogUtilsTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:314e23af09ce3b8bd310bd110ef987fd95404be5)

Change-Id: I4e503533b57619e9c01a549b61af8c7262e4c877