Virtual interfaces for VRR bounced during ifreload -a

Virtual interfaces for VRR bounced during ifreload -a

Ticket: CM-8143
Reviewed By: scotte, roopa
Testing Done: ssim and powerpc

This was first seen as a side issue with switchd terminating and not restarting (filed as CM-8109).

When ifreload -a is issued, all of the vrr interfaces were bounced, even though there were not any
configuration changes.

In keeping with the philosphy of making ifreload non-disruptive, this patch no longer
disrupts vrrs if the existing config has not changed.