[2/2] OmniGears: task utils and navigation bar

http://jira.omnirom.org/browse/OMNI-398
http://jira.omnirom.org/browse/OMNI-345

-added switch to last app as navigation ring target
-added optional kill on long press on back

PS5
rework title

Change-Id: Ia3bed0a2f269904d8e302e75c6e64eb1cfa14663
diff --git a/res/values/custom_strings.xml b/res/values/custom_strings.xml
index 3255bb9..a576cd1 100644
--- a/res/values/custom_strings.xml
+++ b/res/values/custom_strings.xml
@@ -326,6 +326,7 @@
     <string name="navring_action_torch">Toggle torch</string>
     <string name="navring_action_google_now">Google Now</string>
     <string name="navring_choose_action_title">Choose action</string>
+    <string name="navring_action_last_app">Switch to last app</string>
 
     <!-- String for IconPicker -->
     <string name="icon_picker_title">Choose icon source</string>
@@ -394,4 +395,7 @@
     <string name="quick_swipe_title">Quick swipe</string>
     <string name="quick_swipe_summary">Quickly swipe between quick settings and notification drawer</string>
 
+    <!-- navigation bar -->
+    <string name="soft_back_kill_app_title">Long press back to kill app</string>
+    <string name="soft_back_kill_app_summary">Long pressing back button will kill foreground app</string>
 </resources>