Adding additional listeners (onNotificationVisibilityChanged,
onPanelHidden, onPanelRevealed) to NotificationAssistantService.

Bug: 147149509
Test: atest NotificationManagerServiceTest#testOnPanelRevealedAndHidden,testStats_updatedOnVisibilityChanged
Change-Id: If17070677d01b00d7c3cdda9a0e9d3e8f47f9062
8 files changed