Consume bubble entry point in wm shell

1. Update IBubbles to receive the bubble entry point from launcher
2. Set the entry point when dragging taskbar icons to bubbles

This change does not log entry points yet because some ui events
are still missing.

Bug: 438484301
Flag: com.android.wm.shell.enable_create_any_bubble
Test: atest DragToBubbleControllerTest
Change-Id: I1eac4e5526afcdce80f3cafd20c48235c511255f