Localization Changes. Updated apps/settings/locales/settings.en-US.prope...

...rties to match https://bugzilla.mozilla.org/show_bug.cgi?id=798625. Updated apps/settings/locales/settings.en-US.properties and apps/camera/locales/camera.en-US.properties to match https://bugzilla.mozilla.org/show_bug.cgi?id=814856