Add "urn:nfc" shortener.

As defined in the NFC Forum specification
"URI Record Type Definition". For some reason
0x23 wasn't added in the past, but it's present
in the specification.

Change-Id: If4ec2216fd53a31943f6de62aa1c69166f597616
diff --git a/core/java/android/nfc/NdefRecord.java b/core/java/android/nfc/NdefRecord.java
index 2b58818..de481cf 100644
--- a/core/java/android/nfc/NdefRecord.java
+++ b/core/java/android/nfc/NdefRecord.java
@@ -269,6 +269,7 @@
             "urn:epc:pat:", // 0x20
             "urn:epc:raw:", // 0x21
             "urn:epc:", // 0x22
+            "urn:nfc:", // 0x23
     };
 
     private static final int MAX_PAYLOAD_SIZE = 10 * (1 << 20);  // 10 MB payload limit