Restore setGithubButtonId (#1810)

Author: samtstern

CHANGELOG.md

@@ -1 +1,2 @@
 - Fixes issue with custom parameters for OAuth providers (#1805)
+- Restore `setGithubButtonId` when using custom layouts (#1783)

auth/src/main/java/com/firebase/ui/auth/AuthMethodPickerLayout.java

@@ -6,6 +6,7 @@
 
 import com.google.firebase.auth.EmailAuthProvider;
 import com.google.firebase.auth.FacebookAuthProvider;
+import com.google.firebase.auth.GithubAuthProvider;
 import com.google.firebase.auth.GoogleAuthProvider;
 import com.google.firebase.auth.PhoneAuthProvider;
 import com.google.firebase.auth.TwitterAuthProvider;
@@ -158,6 +159,12 @@ public AuthMethodPickerLayout.Builder setAnonymousButtonId(@IdRes int anonymousB
             return this;
         }
 
+        public AuthMethodPickerLayout.Builder setGithubButtonId(
+                @IdRes int githubButtonId) {
+            providersMapping.put(GithubAuthProvider.PROVIDER_ID, githubButtonId);
+            return this;
+        }
+
         public AuthMethodPickerLayout.Builder setMicrosoftButtonId(
                 @IdRes int microsoftButtonId) {
             providersMapping.put(AuthUI.MICROSOFT_PROVIDER, microsoftButtonId);

auth/src/main/java/com/firebase/ui/auth/AuthUI.java

@@ -149,8 +149,7 @@ public final class AuthUI {
     public static final Set<String> SOCIAL_PROVIDERS =
             Collections.unmodifiableSet(new HashSet<>(Arrays.asList(
                     GoogleAuthProvider.PROVIDER_ID,
-                    FacebookAuthProvider.PROVIDER_ID,
-                    GithubAuthProvider.PROVIDER_ID)));
+                    FacebookAuthProvider.PROVIDER_ID)));
 
     @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
     public static final String UNCONFIGURED_CONFIG_VALUE = "CHANGE-ME";