Update Glanceable Hub's AppWidgetHostListener impl for widget events

This change updates GlanceableHub's custom AppWidgetHostListener
implementation to add support for the new collectWidgetEvents method.
This enables event reporting for the hub's widgets.

Bug: 364655296
Test: Manual, use widgets on mobile hub and confirm that they are
 reported
Test: GlanceableHubWidgetManagerServiceTest
Flag: android.appwidget.flags.engagement_metrics

Change-Id: Ic7d69e149d11d8ba03c8c76eaf00f514d5f93418