Istio MeshGateway Deployment lacking status port exposal.

[Tanemahuta]

Describe the bug
Istio MeshGateway Deployment container does not expose status port (15020).

Steps to reproduce the issue:
Deploy a ControlPlane. Deploy a MeshGateway for the CP.

Expected behavior
No errors regarding scraping port.

[Laci21]

#815 merged.