Explicitly pass params to activate_master_ip

To remove the usage of ssconf in the backend, the master needs to push
the parameters of activate_master_ip to the backend.

This patch changes the entire call path of activate_master_ip to use the
new interface.

Signed-off-by: Andrea Spadaccini <spadaccio@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>