Fix the logic to get tv_pip_settings_class_name

Currently, Only the class which is started from "." can be
registered in PipManager. But some activities are not
following this and as the result, Pip is not displayed
in settings bounds even the name is registered in xml.

PipManager checks the class name not only it's started from ".",
but also any class name, then PipManager gets correct class name
even if it's not started from "."

Test: Launch PiP, the activity which is not started from ".".
      Then, open settings.

Change-Id: Iee29596aa8c1955d83338f6dd7a8dcdfccafc906