crdb: replace bc01n03 with dcr01s22, upgrade to v20.2.4

This change reflects the current production state.

Upgrade was done by going through following versions:
19.1.0 -> 19.2.12 -> 20.1.10 -> 20.2.4

Change-Id: I8b33b8116363f1a918423fd18ba3d1b5c910851c
diff --git a/cluster/kube/lib/cockroachdb.libsonnet b/cluster/kube/lib/cockroachdb.libsonnet
index 8ebad52..9f206f0 100644
--- a/cluster/kube/lib/cockroachdb.libsonnet
+++ b/cluster/kube/lib/cockroachdb.libsonnet
@@ -42,7 +42,7 @@
         local cluster = self,
 
         cfg:: {
-            image: "cockroachdb/cockroach:v19.1.0",
+            image: "cockroachdb/cockroach:v20.2.4",
 
             # Must be unique per cluster.
             portServe: 26257,