add mtp responder to TWRP.
Big thanks to Dees_Troy for helping with the implementation.

Change-Id: I6c9c522b9c9de5dc139e2ecb0141008182ba07f0
diff --git a/etc/init.rc b/etc/init.rc
index 39724d0..dda009b 100644
--- a/etc/init.rc
+++ b/etc/init.rc
@@ -23,7 +23,7 @@
 
     write /sys/class/android_usb/android0/enable 0
     write /sys/class/android_usb/android0/idVendor 18D1
-    write /sys/class/android_usb/android0/idProduct D001
+    write /sys/class/android_usb/android0/idProduct D002
     write /sys/class/android_usb/android0/functions adb
     write /sys/class/android_usb/android0/iManufacturer ${ro.product.manufacturer}
     write /sys/class/android_usb/android0/iProduct ${ro.product.model}
@@ -51,6 +51,25 @@
     write /sys/class/android_usb/android0/functions adb
     write /sys/class/android_usb/android0/enable ${service.adb.root}
 
+on property:sys.usb.config=none
+    stop adbd
+    write /sys/class/android_usb/android0/enable 0
+    write /sys/class/android_usb/android0/bDeviceClass 0
+
+on property:sys.usb.config=mtp,adb
+    stop adbd
+    write /sys/class/android_usb/android0/enable 0
+    write /sys/class/android_usb/android0/functions mtp,adb
+    write /sys/class/android_usb/android0/enable 1
+    start adbd
+
+on property:sys.usb.config=adb
+    stop adbd
+    write /sys/class/android_usb/android0/enable 0
+    write /sys/class/android_usb/android0/functions adb
+    write /sys/class/android_usb/android0/enable ${service.adb.root}
+    start adbd
+
 service ueventd /sbin/ueventd
     critical
 
@@ -73,4 +92,4 @@
 on property:service.adb.root=1
     write /sys/class/android_usb/android0/enable 0
     restart adbd
-    write /sys/class/android_usb/android0/enable 1
+    write /sys/class/android_usb/android0/enable 1
\ No newline at end of file