l10n: Change the hour to plural

src/main/res/values/strings.xml

@@ -953,6 +953,6 @@
     <string name="today">Today</string>
     <string name="thirtyMinutes">30 minutes</string>
     <string name="oneHour">1 hour</string>
-    <string name="fourHours">4 hour</string>
+    <string name="fourHours">4 hours</string>
     <string name="thisWeek">This week</string>
 </resources>