Refactor .tv.PipNotification

Make TvPipNotificationController (formerly PipNotification) responsible
for handling broadcasts sent from the Pip StatusBarNotification.
Previouslt TV PipContoller was in charge of that.
Also, as mentioned above, rename PipNotification to
TvPipNotificationController.

Bug: 153784643
Test: atest WMShellFlickerTests:TvPipNotificationTests
Change-Id: Iabdf5ee9d464653e233aee9044ac8cbb26478dea