[UX2.0] Bump the minimum supported version of transport and service routing ospfv3

[seconroy]

Description

Bumps the minimum supported version of transport_routing_ospfv3_ipv4, transport_routing_ospfv3_ipv6, service_routing_ospfv3_ipv4, and service_routing_ospfv3_ipv6 UX2.0 feature to 20.15

Types of Changes

• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)
• Build/CI change
• Code quality improvement/refactoring/documentation (no functional changes)

Checklist

• My code follows the code style of this project
• I have added tests to cover my changes
• All new and existing tests pass locally