Bubbles & TaskOrganizer

Move bubbles off of ActivityView & onto TaskOrganizer. This
mostly impacts BubbleExpandedView, there are a couple of
differences spawning from that:

* taskId is the new thing, displayId's are old news
* No longer need to send back events to the bubble (we can
  set the bubble'd task to intercept now).
* Now we have to subtract the touch region of the activity
  content
* IME insets don't work the "normal" way (?) instead we're
  now using PinnedStackListener for all our IME needs

BubbleTaskView is the ActivityView replacement & it uses
BubbleTaskManager internally to deal with the tasks.

Test: atest BubbleControllerTest BubbleDataTest (existing)
Test: atest MultiWindowTaskListenerTest TaskViewTest
Bug: 148977538
Change-Id: Id6e3bf4950218036b1626481c846ffe57b9ef857