fix: Support http2, grpc protocols in canary release request content …

Created by: leoendless

…policy

Signed-off-by: leoendless leoliu@yunify.com

What type of PR is this?

/kind bug

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #

Special notes for reviewers:

Additional documentation, usage docs, etc.: