Change service port name to use prefix http

[sayanh]

Feature
In order to integrate with Istio, the port name for a function service needs to be have a prefix http-. This enables Istio to discover function services, provided the envoy sidecar is already injected to function pod. Istio has a definite service port naming convention as mentioned here.

Named ports: Service ports must be named. The port names must be of the form [-] with http, http2, grpc, mongo, or redis as the in order to take advantage of Istio’s routing features. For example, name: http2-foo or name: http are valid port names, but name: http2foo is not. If the port name does not begin with a recognized prefix or if the port is unnamed, traffic on the port will be treated as plain TCP traffic (unless the port explicitly uses Protocol: UDP to signify a UDP port).

Implementation details
The implementation is pretty trivial with changing the names of the service ports to http-function-port.

[sayanh]

Please consider this PR as a solution for this issue.

[ngtuna]

@sayanh is there anything you want to do more (why reopen) ? I am seeing the function port name has prefix http- already.

[sayanh]

@ngtuna nothing more actually hence closing.