We saw auto_schedule_routers took over 40 seconds
for a DVR enabled environment with option
auto_schedule_routers enabled.
Adding new arguments to get_router_agents_count and
dealing with routers separately depending on whether
it is a regular router or HA. The benefits are
we do not need to loop over every router available in
environment. Another reason for doing this is that
get_router_agents_count is used solely to heal
routers with less than required agents so number of
routers with less agents is small for most of the times.
Related-Bug: #1973656
Change-Id: Ic29275815a8c32cee7a6470509687a18fa594514
d4654e3011