Update immersive cling dialog

- Layout the dialog under the cutout (but inset the contents if it
  overlaps with the cutout region)
- Update the instruction string
- Update the design to match spec
- Update both WM (old) dialog and SysUI (new) dialog

Flag: EXEMPT bugfix
Fixes: 330912316
Fixes: 315134175
Fixes: 282424060
Test: Verify immersive cling visuals in small/large screen,
      portrait/landscape, with/without display cutouts
Test: adb shell setprop persist.wm.debug.client_immersive_confirmation true/false

Change-Id: I549211b71dcc14c8ba7bc977393af40b9ba0f6c5