Freeze IDnsResolver to v6

Generated with "m dnsresolver_aidl_interface-freeze-api".

Test: m
Bug: 154910763
Change-Id: I6dbd5e0a538a2ed781b94bd855eacc1beb02216f
Merged-In: I6dbd5e0a538a2ed781b94bd855eacc1beb02216f
diff --git a/Android.bp b/Android.bp
index 559b62d..f84f7ab 100644
--- a/Android.bp
+++ b/Android.bp
@@ -49,6 +49,7 @@
         "3",
         "4",
         "5",
+        "6",
     ],
 }