Darwin: DNS service connection reset on interface changes

[dtodor]

Shouldn't this read ResetSharedConnection instead of StartSharedConnection:

https://github.com/project-chip/connectedhomeip/blob/49d7b42d0e732ae63fb0efc8c474f487633da46d/src/platform/Darwin/DnssdHostNameRegistrar.cpp#L275

The callback will be invoked on interface changes and will fail since the connection already exists.