Reland: InputDispatcher: Allow all windows to be removed from a display

Previoulsy reverted for b/240320932. No changes.

Previously, if there were no windows reported on a displayId by the
OnWindowInfosChangedListener, InputDispatcher did not remove the
existing windows from that displayId.

Here, we fix the bug so that when OnWindowInfosChangedListener reports
no windows on a display, the windows are removed from the displayId in
dispatcher.

Bug: 239788987
Test: atest inputflinger_tests
Change-Id: I444cf8c510997742e268d51c358ed78fa48a43f9