Add Http2Origin option to force HTTP/2 origin connections

If `http2Origin` is set, it will set `ForceAttemptHTTP2` in the transport config of the `OriginService`.

config/configuration.go

@@ -227,6 +227,8 @@ type OriginRequestConfig struct {
 	ProxyType *string `yaml:"proxyType" json:"proxyType,omitempty"`
 	// IP rules for the proxy service
 	IPRules []IngressIPRule `yaml:"ipRules" json:"ipRules,omitempty"`
+	// Attempt to connect to origin with HTTP/2
+	Http2Origin *bool `yaml:"http2Origin" json:"http2Origin,omitempty"`
 }
 
 type IngressIPRule struct {