Add sridhargaddam to CODEOWNERS
Related-Issue:
* @mangelajo @tpantelis @Oats87
+/submariner/pkg/globalnet/* @sridhargaddam
+/submariner/pkg/routeagent/* @sridhargaddam
+/submariner/pkg/cable/strongswan/* @sridhargaddam
go.mod @skitt
go.sum @skitt
/package/* @skitt
