Correctly create dialogs so they can be restored.

Previously if you split the screen, opened a dialog, then restored
that part of the screen to full, it would crash.  This ensures we
properly create the dialogs without state, which fixes the crash.

There are still some problems with restoring from full-screen, but
this fixes the crash.

Bug: 123717285
Test: Use dialogs.
Test: Split screen and then use dialogs.
Change-Id: I521a4fe4d6498ec6ee8ffcfc736e2e09ffead73d