Fix hotseat QSB squished issue

Added logic to do not adjust hotseat and QSB if the bubble bar is not
visible.

Test: Manual. Unfold foldable device, open bubbles test application,
trigger bubble via adb, wait until bubble bar is stashed, unfold the
device, go back to the home screen. Observe hotseat and QSB are not
squished.
Flag: com.android.wm.shell.enable_bubble_bar
Fixes: 384903202

Change-Id: Ib03e02d977de6357069470171952afb20c681f20