Fix #35275 (PART2) - TR104: Support multiple SIP accounts

When applying asterisk server URI, asterisk.sip_service_provider.host should take precedence over asterisk.sip_service_provider.domain.

TR104 parameters ...SIP.Network.RegistrarServer and .ProxyServer are all mapped to UCI asterisk.sip_service_provider.host.

Change-Id: I685480308740b9ced922274f6837d0471bdf574c