As per
3b17e06879,
node-local-dns addon is now builded with latest coreDNS base v1.8 and
that brings great consistency between cache and upstream servers in a
manner of configuration, metrics name convention, etc.
So in this commit, we bump node-local-dns image to latest v1.20.0 which
is build upon latest coreDNS and also add support for overriding this
field.
Signed-off-by: dntosas <ntosas@gmail.com>