Log metrics for adding and removing widgets

This change enables logging adding and removing widgets in the
glanceable hub for metrics. A CommunalMetricsLogger is introduced, which
controls that only first party widgets are logged.

Test: atest CommunalMetricsLoggerTest
Test: statsd_testdrive 908
Bug: 317798334
Bug: 317798089
Flag: com.android.systemui.communal_hub
Change-Id: Ice6869a7108339aeb4d3e33ac4dbde98ba0d4d2b