Add a value to customise cloudflared's `--protocol` flag

[sportshead]

QUIC does not work in certain environments, while http2 is more reliable. A configuration value to change the --protocol flag to http2 or others would be quite helpful.

See: https://github.com/cloudflare/cloudflared/issues/617#issuecomment-1414799233

[UnstoppableMango]

It seems like it would be a good idea to allow passing arbitrary args to cloudflared. I took a stab at this in a branch and discovered it was kinda annoying to get a yaml list from helm into the controlled deployment.

[omegazeng]

same issue. any update? I would need this update. thx.

[STRRL]

closed by #72