Sidecar Agones API server should be the first init container

https://github.com/googleforgames/agones/blob/66d89bd811987c9818a26564ce0935ade72ee056/pkg/apis/agones/v1/gameserver.go#L801

This appends the API sidecar server after the init containers in the GameServer template. We should always start the sidecar first.

