This change addresses a NullPointerException (NPE) caused by a postponed
action that relied on controllers. Logic has been added to verify the
availability of controllers prior to checking bubble bar visibility.
Additionally, the destruction sequence of LauncherTaskbarUIController
has been modified: the DeviceProfileListener is now unregistered before
the controller reference is cleared.
Fixes: 396336136
Test: N/A
Flag: EXEMPT bugfix
Change-Id: I1a7f716b3ad0dd4f8431773ea447b95ade4d87ef
mpodolian
c7390ce4e3