[plugin/route53]: Increase ListResourceRecordSets paging size. (#3073)

without the paging parameter set, it will default to 100 records per request. with large enough zones and
potentially multiple coredns daemons configured to pull from route 53, this can quickly add up and reach
aws global api rate limits (5/sec per root account). increasing paging to max can help reduce the number
of requests needed to pull records for a zone without no down side that i am aware of.

this helps issue #2353, but probably is not a complete fix.
Signed-off-by: Matt Kulka <mkulka@parchment.com>

plugin/route53/route53.go

@@ -248,6 +248,7 @@ func (h *Route53) updateZones(ctx context.Context) error {
 				newZ.Upstream = h.upstream
 				in := &route53.ListResourceRecordSetsInput{
 					HostedZoneId: aws.String(hostedZone.id),
+					MaxItems: aws.String("1000"),
 				}
 				err = h.client.ListResourceRecordSetsPagesWithContext(ctx, in,
 					func(out *route53.ListResourceRecordSetsOutput, last bool) bool {