fix secure adb in recovery

Recovery's init.rc was missing a line (added to the main system's
init.rc in change Ic97fd464440ff4a29fc9da7ad15949ac5215ade3) is
required for secure adb to work.

Change-Id: Id79b94d2abb4cbe3cca7cabeb4bc5faf7205e56b
diff --git a/etc/init.rc b/etc/init.rc
index 9d1da1d..1754890 100644
--- a/etc/init.rc
+++ b/etc/init.rc
@@ -51,6 +51,7 @@
 service adbd /sbin/adbd recovery
+    socket adbd stream 660 system system
 # Always start adbd on userdebug and eng builds
 on property:ro.debuggable=1