Update decor LayoutParams when window is already added.

These values can change for themes that are dependent on the size,
such as the DialogWhenLarge theme. In this case, different layouts
are loaded that could depend on updated LayoutParams.

This CL identifies the case when the layoutparams change and informs
the activity.

Change-Id: Icde8d94cc089ca0c02a15120a860533ef540c850
Fixes: 31643268
Test: cts/hostsidetests/services/activityandwindowmanager/util/run-test CtsServicesHostTestCases android.server.cts.ActivityManagerAppConfigurationTests#testDialogWhenLargeSplitSmall