Track pending task info & if the task doesn't launch clean it up

If a task fails to launch, we need to tell clients of TaskView that
the task didn't launch. To do this, we need to have a reference to
TaskInfo so that we can notify clients and actually remove the task.

We know the task failed to launch if it isn't found in the transition
animation. We don't have a reference of the TaskInfo there so we need
to rely on onTaskAppeared to get the info. The order of onTaskAppeared
and the transition animation isn't guaranteed so we set a bit from
the transition if it failed & check that in onTaskAppeared (and vice
versa).

Bug: 283461350
Test: TaskViewTransitionsTest TaskViewTest
Test: manual - must be on tablet with lock, enable home controls to
               show on lockscreen, install CtsDeviceControlsApp and
               add a control (note this only repros because currently
               CtsDeviceControlsApp sets a flag to hide itself on
               lockscreen which manifests the bug)
             - lock the device
             - longpress on homecontrols shortcut icon
             => observe the logs and nothing crashes (although the
                device flickers a lot between lockscreen & controls)
Change-Id: I28e0b2c60889d38f422831935564ef739fd3ef3c
Merged-In: I28e0b2c60889d38f422831935564ef739fd3ef3c