Revert "Revert "Fix mPositionInWindow to not use global coords""

This reverts commit f3cda719.

Reason for revert: Rolling forward with updated test.

Fix is in CTS test:
https://googleplex-android-review.git.corp.google.com/q/topic:screenshot_cts

Bug: 191877447
Change-Id: I058951ce761dc22e8cd1f684ea3f2a98fcf8a8eb