fix(fcm): Remove retry on 500 errors in the default config (#453)

* Remove retry on 500 errors in the default config

Remove retry on 500 errors in the default config

* Update http_client_test.go

* Update ref_test.go

* Update ref_test.go

Co-authored-by: Google Open Source Bot <26440463+google-oss-bot@users.noreply.github.com>

Author: chong-shao

db/ref_test.go

@@ -303,7 +303,7 @@ func TestWelformedHttpError(t *testing.T) {
 		})
 	}
 
-	wantReqs := len(testOps) * (1 + defaultMaxRetries)
+	wantReqs := len(testOps)
 	if len(mock.Reqs) != wantReqs {
 		t.Errorf("Requests = %d; want = %d", len(mock.Reqs), wantReqs)
 	}
@@ -333,7 +333,7 @@ func TestUnexpectedHttpError(t *testing.T) {
 		})
 	}
 
-	wantReqs := len(testOps) * (1 + defaultMaxRetries)
+	wantReqs := len(testOps)
 	if len(mock.Reqs) != wantReqs {
 		t.Errorf("Requests = %d; want = %d", len(mock.Reqs), wantReqs)
 	}

internal/http_client.go

@@ -79,7 +79,6 @@ func WithDefaultRetryConfig(hc *http.Client) *HTTPClient {
 		RetryConfig: &RetryConfig{
 			MaxRetries: 4,
 			CheckForRetry: retryNetworkAndHTTPErrors(
-				http.StatusInternalServerError,
 				http.StatusServiceUnavailable,
 			),
 			ExpBackoffFactor: 0.5,

internal/http_client_test.go

@@ -733,7 +733,7 @@ func TestNewHTTPClientRetryOnHTTPErrors(t *testing.T) {
 
 	client.RetryConfig.ExpBackoffFactor = 0
 	client.SuccessFn = acceptAll
-	for _, status = range []int{http.StatusInternalServerError, http.StatusServiceUnavailable} {
+	for _, status = range []int{http.StatusServiceUnavailable} {
 		requests = 0
 		req := &Request{Method: http.MethodGet, URL: server.URL}
 		resp, err := client.Do(context.Background(), req)