Fixed monkey test failure

Avoid duplicate attempt to remove WindowToken from its parent
container when removeImmediately is called by first removing the
token from the display before calling super.removeImmediately
which only tries to remove the child from the parent container
if it is still attached to the parent.

Also, added test for the failure case the monkey test was
triggering.

Bug: 32239922
Test: WindowTokenTests.testChildRemoval passes
Change-Id: I4153669d18260d956c4b570944d2f48516d692ac