Add a new UEventObserver subclass to broadcast an Intent whe USB state changes.

We now broadcast Usb.ACTION_USB_CONNECTED and Usb.ACTION_USB_DISCONNECTED
when USB is connected or disconnected.
The ACTION_USB_CONNECTED extras indicate the enabled/disabled state of
all USB functions.

Change-Id: I919fcd5aa8d640d051cec87053f474a9843ed545
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 5cdfc1d..e044c2a 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -80,6 +80,9 @@
     <protected-broadcast android:name="android.bluetooth.device.action.PAIRING_REQUEST" />
     <protected-broadcast android:name="android.bluetooth.device.action.PAIRING_CANCEL" />
 
+    <protected-broadcast android:name="android.hardware.action.USB_CONNECTED" />
+    <protected-broadcast android:name="android.hardware.action.USB_DISCONNECTED" />
+
     <!-- ====================================== -->
     <!-- Permissions for things that cost money -->
     <!-- ====================================== -->