Specify transition handler for window drag across displays

`DefaultTransitionHandler` triggers `startBoundsChangeAnimation` when
`onConfigurationChanged` creates a `snapshot` due to width or height
changes. Dragging a task across displays with different DPIs can change
the task's actual width and height. This is expected, but the animation
is unnecessary and visually distracting since we have drag indicator
surfaces that follow the cursor, providing sufficient visual feedback
to the user.
This change specifies a transition handler that has no animation for
window drag across displays.

Bug: 390370556
Bug: 397354255
Test: Manual
Flag: com.android.window.flags.enable_connected_displays_window_drag
Change-Id: I79ba64abdd6f75f9ab65fd7c98df63707e2255db