Add README.md explanation

Author: SUPERCILEX

auth/README.md

@@ -57,6 +57,12 @@ repositories {
 }
 ```
 
+#### Important note
+
+Firebase-UI-auth v1.0.0 is incompatible with the v25 support libraries. Please upgrade to v1.0.1
+to use the latest version of the support libraries.
+
+
 ### Identity provider configuration
 
 In order to use either Google, Facebook or Twitter accounts with your app, ensure that

auth/src/main/java/com/firebase/ui/auth/provider/FacebookProvider.java

@@ -19,7 +19,6 @@
 import android.content.Intent;
 import android.os.Bundle;
 import android.util.Log;
-
 import com.facebook.CallbackManager;
 import com.facebook.FacebookCallback;
 import com.facebook.FacebookException;
@@ -35,12 +34,10 @@
 import com.firebase.ui.auth.R;
 import com.google.firebase.auth.AuthCredential;
 import com.google.firebase.auth.FacebookAuthProvider;
-
-import org.json.JSONException;
-import org.json.JSONObject;
-
 import java.util.ArrayList;
 import java.util.List;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 public class FacebookProvider implements IdpProvider, FacebookCallback<LoginResult> {
     protected static final String ERROR = "err";

auth/src/main/java/com/firebase/ui/auth/ui/idp/AuthMethodPickerActivity.java

@@ -89,18 +89,18 @@ private void populateIdpList(List<IdpConfig> providers) {
         mIdpProviders = new ArrayList<>();
         for (IdpConfig idpConfig : providers) {
             switch (idpConfig.getProviderId()) {
-                case AuthUI.GOOGLE_PROVIDER:
-                    mIdpProviders.add(new GoogleProvider(this, idpConfig));
-                    break;
                 case AuthUI.FACEBOOK_PROVIDER:
                     mIdpProviders.add(new FacebookProvider(this, idpConfig));
                     break;
-                case AuthUI.TWITTER_PROVIDER:
-                    mIdpProviders.add(new TwitterProvider(this));
+                case AuthUI.GOOGLE_PROVIDER:
+                    mIdpProviders.add(new GoogleProvider(this, idpConfig));
                     break;
                 case AuthUI.EMAIL_PROVIDER:
                     findViewById(R.id.email_provider).setVisibility(View.VISIBLE);
                     break;
+                case AuthUI.TWITTER_PROVIDER:
+                    mIdpProviders.add(new TwitterProvider(this));
+                    break;
                 default:
                     if (BuildConfig.DEBUG) {
                         Log.d(TAG, "Encountered unknown IDPProvider parcel with type: "

common/constants.gradle

@@ -1,4 +1,6 @@
 project.ext.firebase_version = '9.8.0'
+// use caution when updating support library version, v25.0.0 caused issues
+// with the Facebook SDK. (NoSuchMethodError startActivity)
 project.ext.support_library_version = '25.0.0'
 
 project.ext.submodules = ['database', 'auth', 'storage']