Fix Mobile Install Referrer issue for MMP integration

Summary: Remove "fb" prefix for Android App Id to fix MIR issue for MMP integration.

Reviewed By: KylinChang

Differential Revision: D56906371

fbshipit-source-id: f7a2271b638b38bebc59ae8dff2df057e231b6a2

Facebook.Unity.Editor/android/ManifestMod.cs

@@ -158,10 +158,10 @@ public static void UpdateManifest(string fullPath)
             ManifestMod.AddSimpleActivity(doc, dict, ns, UnityGameRequestActivityName);
 
             // add the app id
-            // <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\ fb<APPID>" />
+            // <meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\ <APPID>" />
             XmlElement appIdElement = doc.CreateElement("meta-data");
             appIdElement.SetAttribute("name", ns, ApplicationIdMetaDataName);
-            appIdElement.SetAttribute("value", ns, "fb" + appId);
+            appIdElement.SetAttribute("value", ns, appId);
             ManifestMod.SetOrReplaceXmlElement(dict, appIdElement);
 
             // add the client token