Align hotseat drop target with the adjusted hotseat

Added logic to adjust the drop target to account for changes in the
hotseat position when accommodating the bubble bar.

Fixes: 382348730
Test: all tests in package src.com.android.launcher3.celllayout
Test: Manual. Ensure bubbles are present, and the hotseat width is
adjusted. Long-press any icon in the hotseat, begin dragging it over
other hotseat icons, and observe that the drop target is drawn
appropriately.
Flag: com.android.wm.shell.enable_bubble_bar

Change-Id: Ice961f40ace03077ab8c9312a93eda1a16d7da34
3 files changed