Navbar: Switch gesture navbar to new navigation bar key event source

- Fixes issue with back gesture not working while using custom key
policy

Change-Id: Ie10da1b8acfc7e5b87a6e9c107e6666eca1aa0d1
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

Author: Alex

packages/SystemUI/src/com/android/systemui/statusbar/phone/EdgeBackGestureHandler.java

@@ -574,7 +574,7 @@ private void sendEvent(int action, int code, int flags) {
         final KeyEvent ev = new KeyEvent(when, when, action, code, 0 /* repeat */,
                 0 /* metaState */, KeyCharacterMap.VIRTUAL_KEYBOARD, 0 /* scancode */,
                 flags | KeyEvent.FLAG_FROM_SYSTEM | KeyEvent.FLAG_VIRTUAL_HARD_KEY,
-                InputDevice.SOURCE_KEYBOARD);
+                InputDevice.SOURCE_NAVIGATION_BAR);
 
         // Bubble controller will give us a valid display id if it should get the back event
         BubbleController bubbleController = Dependency.get(BubbleController.class);