add default access to RestAuthProvider

Author: anotherdev

firebase-auth-rest/core/src/main/java/com/anotherdev/firebase/auth/rest/RestAuthTokenRefresher.java

@@ -25,6 +25,7 @@ public class RestAuthTokenRefresher implements IdTokenListener, LifecycleObserve
     private static final long MAX_RETRY_BACKOFF = MILLISECONDS.convert(5, MINUTES);
 
     private final Handler handler = new Handler();
+    @NonNull
     private final RestAuthProvider auth;
 
     private String ownerName;
@@ -33,10 +34,15 @@ public class RestAuthTokenRefresher implements IdTokenListener, LifecycleObserve
     private String lastToken;
 
 
-    public RestAuthTokenRefresher(RestAuthProvider auth) {
+    public RestAuthTokenRefresher(@NonNull RestAuthProvider auth) {
         this.auth = auth;
     }
 
+    @NonNull
+    RestAuthProvider getAuth() {
+        return auth;
+    }
+
     @Override
     public void onIdTokenChanged(@NonNull InternalTokenResult result) {
         final String newToken = result.getToken();