[auth][android] Add methods to set the auth language via code or device language

android/src/main/java/io/invertase/firebase/auth/RNFirebaseAuth.java

@@ -1129,6 +1129,7 @@ class RNFirebaseAuth extends ReactContextBaseJavaModule {
   /**
    * fetchProvidersForEmail
    *
+   * @param appName
    * @param promise
    */
   @ReactMethod
@@ -1163,6 +1164,31 @@ class RNFirebaseAuth extends ReactContextBaseJavaModule {
       });
   }
 
+  /**
+   * Set the language code for the auth module
+   * @param appName
+   * @param code
+   */
+  @ReactMethod
+  public void setLanguageCode(String appName, String code) {
+    FirebaseApp firebaseApp = FirebaseApp.getInstance(appName);
+    FirebaseAuth firebaseAuth = FirebaseAuth.getInstance(firebaseApp);
+
+    firebaseAuth.setLanguageCode(code);
+  }
+
+  /**
+   * Use the device language
+   * @param appName
+   */
+  @ReactMethod
+  public void useDeviceLanguage(String appName) {
+    FirebaseApp firebaseApp = FirebaseApp.getInstance(appName);
+    FirebaseAuth firebaseAuth = FirebaseAuth.getInstance(firebaseApp);
+
+    firebaseAuth.useAppLanguage();
+  }
+
   /* ------------------
    * INTERNAL HELPERS
    * ---------------- */

lib/modules/auth/index.js

@@ -322,6 +322,23 @@ export default class Auth extends ModuleBase {
     return this._native.fetchProvidersForEmail(email);
   }
 
+  /**
+   * Sets the language for the auth module using the device language
+   * @returns {*}
+   */
+  useDeviceLanguage() {
+    return this._native.useDeviceLanguage();
+  }
+
+  /**
+   * Sets the language for the auth module
+   * @param code
+   * @returns {*}
+   */
+  set languageCode(code) {
+    return this._native.setLanguageCode(code);
+  }
+
   /**
    * Get the currently signed in user
    * @return {Promise}