fix(fcm): Increase FCM timeout to 15s (#1947)

Author: lahirumaramba

src/messaging/messaging-api-request-internal.ts

@@ -27,7 +27,7 @@ import { SendResponse, BatchResponse } from './messaging-api';
 
 
 // FCM backend constants
-const FIREBASE_MESSAGING_TIMEOUT = 10000;
+const FIREBASE_MESSAGING_TIMEOUT = 15000;
 const FIREBASE_MESSAGING_BATCH_URL = 'https://fcm.googleapis.com/batch';
 const FIREBASE_MESSAGING_HTTP_METHOD: HttpMethod = 'POST';
 const FIREBASE_MESSAGING_HEADERS = {

test/unit/messaging/messaging.spec.ts

@@ -3538,7 +3538,7 @@ describe('Messaging', () => {
             expect(httpsRequestStub).to.have.been.calledOnce.and.calledWith({
               method: 'POST',
               data: { message: expectedReq },
-              timeout: 10000,
+              timeout: 15000,
               url: 'https://fcm.googleapis.com/v1/projects/project_id/messages:send',
               headers: expectedHeaders,
             });