Defer display content removal on disconnect.

Currently, display content is removed as part of transaction handling in WindowOrganizerController. However, this can interfere with other task changes in the same transaction as this occurs before handling of hierarchy ops. To fix this, move the display content removal to after hierarchy ops handling in WindowOrganizerController#applyTransaction.

Bug: 435672235
Test: Manual
Flag: com.android.window.flags.enable_display_disconnect_interaction

Change-Id: I812760d1c6159f8ec166b70f03bbdca60900c6a9