First pass at USB Tethering.

bug:2281900
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 665088a..1406b66 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -1239,6 +1239,10 @@
                 <category android:name="android.intent.category.DEFAULT" />
             </intent-filter>
         </activity>
+        <activity android:name="com.android.internal.app.TetherActivity"
+                android:theme="@style/Theme.Dialog.Alert"
+                android:excludeFromRecents="true">
+        </activity>
         <activity android:name="com.android.internal.app.UsbStorageActivity"
                 android:excludeFromRecents="true">
         </activity>