Check callbacks when operting on UI

This makes sure that only the session that current owns the UI can make
changes to the UI:

The callback is the ID of the current owner. The only caller that does
not ID itself (and thereby causes the Ui to close in any way) is the
ACTION_CLOSE_SYSTEM_DIALOGS path.

Change-Id: Ib396864411f362b59deb500251c37896ecbc7de7
Fixes: 38042845
Test: CtsAutoFillServicesTestCases