autofill: fix window location in splitwindow and dialog

autofill should use relative location to app window as PopupWindow
is based on relative location.

The fixed reverted changes made in compatibility mode CL that made
autofill window TYPE_SYSTEM_DIALOG.

Changing PopupWindow to use absolute screen location is another fix
choice, but it does not allow autofill window to be automatically
moved when app window changes location (e.g. adjust split window
separator or bring up IME)

The autofill window switches to TYPE_APPLICATION_ABOVE_SUB_PANEL with
IME disabled. So it still appears above IME and most other app
windows, unless app window is TYPE_APPLICATION_ABOVE_SUB_PANEL too.

Fixes: 73555917
Bug: 77587135
Test: manually tested compability mode with chrome amazon login
      manually tested splitted window
      atest CtsAutoFillServiceTestCases

Change-Id: I6b8ecf3fe7a91cebea1f7a868f4b15fbed8b0051