discovery: fix jni & moments app

   - Fix bugs in discovery jni
   - Update moments app with a new discovery API

MultiPart: 1/2
Change-Id: Idf1233f75aca22804293ba9d0a95ae56268e216f
diff --git a/impl/google/discovery/plugins/jni.go b/impl/google/discovery/plugins/jni.go
index 7687b42..3fafd24 100644
--- a/impl/google/discovery/plugins/jni.go
+++ b/impl/google/discovery/plugins/jni.go
@@ -20,7 +20,7 @@
 var (
 	androidContextSign = jutil.ClassSign("android.content.Context")
 	adInfoSign         = jutil.ClassSign("io.v.x.ref.lib.discovery.AdInfo")
-	scanHandlerSign    = jutil.ClassSign("io.v.impl.google.lib.discovery.Plugin.ScanHandler")
+	scanHandlerSign    = jutil.ClassSign("io.v.impl.google.lib.discovery.Plugin$ScanHandler")
 
 	jAdInfoClass            jutil.Class // io.v.x.ref.lib.discovery.AdInfo
 	jNativeScanHandlerClass jutil.Class // io.v.android.impl.google.discovery.plugins.NativeScanHandler
diff --git a/impl/google/discovery/plugins/plugin.go b/impl/google/discovery/plugins/plugin.go
index 06b1eb1..4660a6e 100644
--- a/impl/google/discovery/plugins/plugin.go
+++ b/impl/google/discovery/plugins/plugin.go
@@ -93,8 +93,7 @@
 		env, freeFunc := jutil.GetEnv()
 		defer freeFunc()
 
-		jHost := jutil.JString(env, host)
-		jPlugin, err := jutil.NewObject(env, jPluginClass, []jutil.Sign{jutil.StringSign, androidContextSign}, jHost, jAndroidContext)
+		jPlugin, err := jutil.NewObject(env, jPluginClass, []jutil.Sign{androidContextSign, jutil.StringSign}, jAndroidContext, host)
 		if err != nil {
 			return nil, err
 		}