Remove widget from hub when its package is uninstalled

Test: atest CommunalAppWidgetHostTest
Test: atest CommunalAppWidgetHostStartableTest
Test: verify from UI and logs that uninstalled widgets are properly
removed
Bug: 322170342
Fix: 322170342
Flag: ACONFIG com.android.systemui.communal_hub STAGING

Change-Id: I9cd508c97d8c3a9a2aedf1a98ded7c81e32238dc