1. If an accessibility service uses an invalid focus type argument
when trying to find where focus is the queried application crashes.
The same happens if the serivce calls focus search with an invalid
derection. While we need the argument check in the controller that
runs in the app process the accessibility service has to be the
palace where an exception is thown for the invalid argument so
the developer can fix his code.:
bug:6508797
Change-Id: Ib0d74f374fa60ee8fd6117f11c23af34f6c26ad3