Remove touch listener when disposing input layer.

When removing the status bar input layer, set the touch listener of the
view to null immediately. This fixes an edge case where the touch
listener can attempt to process input for a decor that has been recently
closed.

Bug: 387452764
Test: Manual
Flag: com.android.window.flags.enable_desktop_windowing_mode
Change-Id: I277b19e5395b1ba8736c57a18ca0196276150b1f