Add missing seinfo tag from mac_permissions.xml policy.

A prior merge accidentally dropped the seinfo tag from the
release keys stanza.

Change-Id: I99f9ea8d0981c5324c3875896b0673552a03d2ca
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>

mac_permissions.xml

 <?xml version="1.0" encoding="utf-8"?>
 <policy>
 
+    <!-- Platform dev key in AOSP -->
     <signer signature="@PLATFORM" >
       <seinfo value="platform" />
     </signer>
@@ -17,6 +18,7 @@
 
     <!-- release dev key in AOSP -->
     <signer signature="@RELEASE" >
+      <seinfo value="release" />
     </signer>
 
     <!-- All other keys -->