jni: Upgrade NFD/ndn-cxx to version 0.6.6

Change-Id: I27feb9fa93d8c3d0533d04bb3646a9fd80f0289b
diff --git a/app/build.gradle b/app/build.gradle
index ff8edc6..5d276d4 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -9,8 +9,8 @@
         applicationId "net.named_data.nfd"
         minSdkVersion 23
         targetSdkVersion 27
-        versionCode 4012
-        versionName "0.6.5-3 (NFD 0.6.5)"
+        versionCode 4013
+        versionName "0.6.6-1 (NFD 0.6.6)"
         multiDexEnabled true
     }
     compileOptions {