overlay: Enable “Panic Detection” mode

* Change Ibf1370ff3cb539a9a54002a8704922744a3ca5d7 on fw/base
   added support for a security feature. This feature listens
   for multiple back button presses in succession and then
   returns the user to their home screen.

Change-Id: I5a386782ae2dcb0898491e1af48a73d6fb74a181

overlay/common/frameworks/base/core/res/res/values/config.xml

@@ -75,4 +75,10 @@
     <!-- If this is true, long press on power button will be available from a
          non-interactive state. -->
     <bool name="config_supportLongPressPowerWhenNonInteractive">true</bool>
+
+    <!-- Control the behavior when the user panic presses the back button.
+            0 - Nothing
+            1 - Go to home
+    -->
+    <integer name="config_backPanicBehavior">1</integer>
 </resources>