Account for bubble bar bounds for taskbar overflow

When caculating number of icons to show in taskbar, account for bubble
bar size (the max size when in collapsed state) when bubble bar has
bubbles (even if the bubble bar is stashed). Note that the bubble bar
visibility may change, so max number of icons in the taskbar may change
during the taskbar view lieftime. TaskbarViewController already had a
method called when the bubble bar visibility changed - adapt it to also
reclaculate max number of icons to show in the taskbar, and update the
list of icons shown in the UI if necessary (if the change in the bubble
bar visibility would also cause a change in number of icons shown in the
taskbar).

Bug: 368119679
Test: Launch enough apps for taskbar to enter overflow, open an app that
supports bubbles, and trigger 2 or more bubbles so bubble bar shows up.
Verify that the buble bar does not overlap with taskbar bounds, both
in transient and persistent taskbar. Remove bubbles, and verify the
taskbar bounds expand, allowing more icons to be shown.
Flag: com.android.launcher3.taskbar_overflow

Change-Id: Ifed4e5e5dd64df5256090f5ba55f24203c09e839