Fix AccessibilityGestureDispatchTest start point

In this test, mStartPoint is a location on screen. However, in each test
cases, these bounds are used **WithinView() method, which expects the
arguments relative from the top-left of the TextView.
This works when the window is launched as full screen, but doesn't when
it is launched as a freefrom window.

This change fixes mStartPoint to have the relative location to the
TextView.

Bug: 162282247
Test: atest AccessibilityGestureDispatchTest (in ARC (eve-arc-r) and crosshatch)
Change-Id: Ia5ea878ec717e2a45a658c537ed13729894a31ed
1 file changed