Add retriable headers field for Retry Policy

[shalier]

Please describe the Improvement and/or Feature Request

For the retryOn field in retry policy, you can set it to various policies that Envoy has set https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/router_filter#x-envoy-retry-on One of the policies is retriable_headers, which when set would have allowed users more control over what to retry on https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/router_filter#x-envoy-retriable-header-names Currently, that policy isn't functional at the moment, since we don't have a retriable_headers field where the user would be able to specify what to retry on.

Scope (please mark with X where applicable)

• New Functionality [X ]

Possible use cases

[github-actions[bot]]

Added default label kind/needed. Please consider re-labeling this issue appropriately.

[github-actions[bot]]

This issue will be closed due to a long period of inactivity. If you would like this issue to remain open then please comment or update.

[mudit-01]

I can work on this

[mudit-01]

Pls assign it to me

[github-actions[bot]]

This issue will be closed due to a long period of inactivity. If you would like this issue to remain open then please comment or update.

[github-actions[bot]]

Issue closed due to inactivity.