Add Default Exclusion for Istio Gateways for Gatekeeper

Currently, the gatekeeper policy for noSysctls is causing gateways for operatorless istio to continuously restart. The goal would be to make sure the new gateways run without issue if gatekeeper is in use without users having to add custom exclusions.

• Check if the same problem exists with current istio implementation
• Investigate removing permissions from gateway to see if exclusion can be avoided
• If previous cannot be done, add exclusion to the umbrella chart for Gatekeeper so it automatically applies to all gateways.