update:更新flexion 以及sdk 接入

ExtraPluginCfgs/Android/flexion/ChannelHelpers.java

@@ -0,0 +1,9 @@
+package com.unity3d.player;
+
+public class ChannelHelpers {
+    public static final String CHANNEL = "Flexion";
+
+    static void register() {
+        SDKManager.registerHelper(CHANNEL, new FlexionSDKHelper());
+    }
+}