Fix touchable region calculation in NavigationBarController (2nd)

As ViewTreeObserver.InternelInsetsInfo.touchableRegion with setting
TOUCHABLE_INSETS_REGION requires setting the region that relative
the window position, but CL[1] uses the global screen position to
calculate the touch region, which will affect the end result,

To fix this, we should use getLocationInWindow to get the relative
position of the window.

[1]: I0fe54efac80dd0d55f4ba37cfa7d7188b642abb0
Fix: 229562319
Test: manually verified with the IME mentioned in the bug.
Test: ensure Bug 226566506 is verified.

Change-Id: I9e3fe45dccb263445d378b5ac17b0e450bdb1c24