Create TunnelConnectionParams interface

TunnelConnectionParams represents configurations for setting up a
secure encrypted tunnel with a remote endpoint. TunnelConnectionParams
will be used to configure a VCN and will be used for VPN configuration
in the future.

Bug: 180664474
Test: make update-api
Change-Id: Ic8e5c8535e84971517f16c54ce8b8645cfc7f944