Cutout emulation: string changes and ordering

Updates strings according to spec. Also ensures
that the emulation overlays are shown in the
order of their priority.

Bug: 112876936
Test: Open developer options, go to "display cutout", verify strings.
Change-Id: If2d05595d02a277896202ab2a6262c99508a3a17
Merged-In: If2d05595d02a277896202ab2a6262c99508a3a17