Restore initial location after drag to dismiss

When dragging bubble bar expanded view, bar or a bubble, restore the
initial location when dragging and releasing the view in the dismiss
target.

Bug: 339659499
Flag: com.android.wm.shell.enable_bubble_bar
Test: atest WMShellRobolectricTests:BubbleExpandedViewPinControllerTest
Test: atest WMShellMultivalentTestsOnDevice:BubbleExpandedViewPinControllerTest
Test: manual
  - drag expanded view to left, then to dismiss, release
    - bubble bar should be back on right side
  - drag expanded view to dismiss and back out
    - there should be no drop target
  - drag expanded view to dismiss and to left side
    - drop target shows up on left side
  - drag expanded view to left, to dismiss, to right
    - drop target shows up on right side
Change-Id: I167523656b97e22dcfbdb723e30e72c6e4170363