Add AppWidgetManager.queryAppWidgetEvents API

This changes add queryAppWidgetEvents API to query widget interaction
events for widgets provided by the calling process. Internally, it uses
UsageStatsManager to query usage events.

Bug: 364655296
Test: CtsAppWidgetTestCases:WidgetEventsTest
Flag: android.appwidget.flags.engagement_metrics
Change-Id: I922caf67366bcb9ec21442f4689167d39623288b