update： 优化引用位置

Signed-off-by: huyufei <yufei.hu@castbox.fm>

Runtime/GuruCore/Runtime/Firebase/FirebaseUtil.cs

@@ -1,4 +1,3 @@
-using Firebase.Auth;
 
 namespace Guru
 {
@@ -6,6 +5,7 @@ namespace Guru
 	using Firebase;
 	using Firebase.Analytics;
 	using Firebase.Extensions;
+	using Firebase.Auth;
 	using UnityEngine;
 	
 	public static partial class FirebaseUtil
@@ -213,5 +213,6 @@ namespace Guru
 		}
 		
 		#endregion
+
 	}
 }