Align moving display to top behavior

The behavior of moving a display to top was different based on
perDisplayFocusEnabled. In the perDisplayFocusEnabled=true case only a
tap on the screen, but not a targeted key would move the display to the
top. To simplify the logic this change makes
the behavior the same for both cases: A targeted key, as well as a touch
on a display moves that display to top.

See also b/121057974, which introduced the behavior.
Note that this change does not affect the window focus behavior.
Displays have a window focus anyway with perDisplayFocusEnabled=true.
Note that the behavior for perDisplayFocusEnabled=false stays unchanged.

Bug: 254161477
Test: atest "CtsWindowManagerDeviceTestCases:android.server.wm.WindowFocusTests"
Test: atest "CtsWindowManagerDeviceTestCases:android.server.wm.MultiDisplayPolicyTests"
Change-Id: I52467f028b012ac2abdcb1838d4752e5e4bc4693