implement activity blocking

- monitor activity launch and shut it down if
  car is not parked and if the app is not allowed.
- Launch blocking activity for unsafe app.
- Blocking activity stays up to timeout (3 secs) and
  finish itself if there is safe app behind.
  If safe app is not there, launch home. If home is
  not safe either. stay.
- allow OEMs to give static whitelist as overlay.

bug: 25267050

Change-Id: Id0bdae757fa98345069f2d83711b46447506f888
diff --git a/service/res/values/strings.xml b/service/res/values/strings.xml
index e412903..f97efc4 100644
--- a/service/res/values/strings.xml
+++ b/service/res/values/strings.xml
@@ -78,4 +78,9 @@
     <!-- Notification text: Notification description shown to the user when vehicle CAN bus fails -->
     <string name="car_can_bus_failure_desc">CAN bus does not respond. Unplug and plug back headunit
         box and restart the car</string>
+
+    <!--  Blocking activity: Message to show to user when an application is not allowed. [CHAR LIMIT=NONE] -->
+    <string name="activity_blocked_string">The application is not allowed while driving.</string>
+    <!--  Blocking activity: Message on exit button. [CHAR LIMIT=NONE] -->
+    <string name="exit_now">Exit</string>
 </resources>