Application with app-metrics enabled gets timeout after 15 seconds.

[dheeth]

Checklist:

• [x] I've searched in the docs and FAQ for my answer
• [x] I've included steps to reproduce the bug.

Describe the bug

One of our app takes more than 15 seconds to get response from the API but if app-metrics are enabled on the app, it gets timed out after 15 seconds no matter what timeout we define. This happens due to envoy default Route Timeout which is 15 seconds by default. Route Timeout

To Reproduce

1. Deploy an app with app-metrics enabled
2. Hit an endpoint which takes more than 15 seconds to respond
3. It will end the connection after 15 seconds
4. Disable app-metrics and deploy again
5. Hit the same endpoint again and you'll get required response this time without any issues even if it takes more than 15 seconds

Expected behavior

It shouldn't timeout even with app-metrics enabled or route-timeout should be configurable

Current behavior

Due to route-timeout the application couldn't take time as needed to provide the response

AB#436