WM: Switch to using APPLICATION_OVERLAY window type for ErrorDialogs

SYSTEM_ALERT window type is deprecated and they will be placed below APPLICATION_OVERLAY
windows. If an ANR dialog is shown for an app that is currently drawing windows of type
APPLICATION_OVERLAY, the dialog may not be shown.

Bug: 119559674
Test: Manual test with anr dialogs + presubmit
Change-Id: I3aa09ee9ac6b30989c399eae9f305240a638307c