Bring dummy cling strings back as 'strings'

The translations import recognizes 'string', 'string-array' and
'plurals' as valid items to parse, all others are ignored.  This is the
reason, why these strings have not been imported back into the codebase.
Making the string declaration same as when it was removed in cl/236665

Change-Id: I6d53ba9d6267706834cb66e9ca99a1335aa01d14
Bug: 7203884
1 file changed