Fix strings for support tab.

Bug: 29105266

- Fix typos in string and comments
- Use 2 different strings for off-hour and off-line cases.

Change-Id: I63859605ff7185d5f8cc66fd31b56f1d09ed11aa

src/com/android/settings/overlay/SupportFeatureProvider.java

@@ -71,7 +71,8 @@ public interface SupportFeatureProvider {
      * Returns localized string for operation hours in specified country. If country is null, use
      * current country to figure out operation hours.
      */
-    CharSequence getOperationHours(Context context, @SupportType int type, String countryCode);
+    CharSequence getOperationHours(Context context, @SupportType int type, String countryCode,
+            boolean hasInternet);
 
     /**
      * Returns a localized string indicating estimated wait time for a support time.