aapt: Allow raw "%" in unformatted string-arrays

Commit 15fe2cb added format checking for translatable strings, enforcing
the use of positional args.  This check can be disabled on <string>
values with translatable="false" or formatted="false".  But they didn't
check for those attributes on <string-array>, so some of CM's strings
fail when they're not really format strings, just because they contain
percent signs.  (e.g. brightness widget's "Auto/Dim/40%/100%")

So now the formatted/translatable attributes are checked in string-array
too, and we can restore our proper percent signs.

Change-Id: I3478ab7e0b939e61fe0cec20201ac55096264080