Use shellRoot to identify PIP menu window

Pip menu is an untouchable window which is exculded
from accessibility windows list. However it is touchable
when users touch in the pip mode window.

To fix it, we add this window to visible windows
list by comparing the window token.

Bug: 191736824
Test: a11y CTS & unit tests
Change-Id: I0ac0d0487d0bec9ef04a2ba5770ba499d5125b11
3 files changed