make summary of passphrase timeout translatable

//FREEBIE

res/values/strings.xml

@@ -42,6 +42,9 @@
     <string name="ApplicationPreferencesActivity_incoming_sms">Incoming</string>
     <string name="ApplicationPreferencesActivity_outgoing_sms">outgoing</string>
 
+    <!-- AppProtectionPreferenceFragment -->
+    <string name="AppProtectionPreferenceFragment_minutes">%d minutes</string>
+
     <!-- DraftDatabase -->
     <string name="DraftDatabase_Draft_image_snippet">(image)</string>
     <string name="DraftDatabase_Draft_audio_snippet">(audio)</string>

src/org/thoughtcrime/securesms/preferences/AppProtectionPreferenceFragment.java

@@ -69,7 +69,7 @@ public class AppProtectionPreferenceFragment extends PreferenceFragment {
   private void initializeTimeoutSummary() {
     int timeoutMinutes = TextSecurePreferences.getPassphraseTimeoutInterval(getActivity());
     this.findPreference(TextSecurePreferences.PASSPHRASE_TIMEOUT_INTERVAL_PREF)
-        .setSummary(String.format("%d minutes", timeoutMinutes));
+        .setSummary(getString(R.string.AppProtectionPreferenceFragment_minutes, timeoutMinutes));
   }
 
   private class ChangePassphraseClickListener implements Preference.OnPreferenceClickListener {