Update expanded view drop target size based on value from shell

When a bubble drag starts, shell sends the current expanded view size
over as part of BubbleBarData. Update the size stored in
BubblePinController based on latest value.
Update drop target visual to match the spec. It should have 24dp insets
compared to expanded view and 28dp corner radius.

Bug: 330585402
Test: drag bubble in landscape, check that drop target for expanded view
  matches with what is shown when expanded view is dragged
Test: drag bubble in portrait, check that the drop target for expanded
  view, matches with what is shown when expanded view is dragged
Flag: ACONFIG com.android.wm.shell.enable_bubble_bar DEVELOPMENT
Change-Id: Ic11c4c5c675107543ba08f24a4138cda422d24c1