Strings updates for the new version of High contrast text.

These strings may be replaced again after our UX Writing team provides
new strings for the final public release.

Bug: 384791485
Test: observe new strings; see http://b/384791485#comment2
Flag: EXEMPT strings changes
Change-Id: I5359bc3d6faca84238fe00801a5d68e5ef8ffc2f
5 files changed