Revert "Fix low battery warnings on lockscreen on some languages"

This reverts commit 6cdb332a6fe4c9699e626b772ae66a078d25e195.

The root cause for the bug this commit aimed to fix was a broken usage
of that string in the fingerprint unlock screen, which is not even in
CyanogenMod yet. As the other lockscreens (LockScreen.java,
PatternUnlockScreen.java) properly include the battery level information
and as the English version of that string (in values/strings.xml)
includes that information as well, there's no reason to hide it from
users of certain locales, especially as those will feel that it's a
regression if we do so.