Fix a11y window positions

We need to undo the exact steps in getTransformationMatrix
that were done by transformFrameToSurfacePosiition. Also added
a comment that these two methods should be mirrored.

Test: atest
android.autofillservice.cts.DialogLauncherActivityTest#testAutofill_oneDataset
Fixes: 70790228
Bug: 64674361

Change-Id: I84ee6a6acfe4f59f18b4e446eb1fd18b1b2e1eba