Push ETCD defrag threshold to 75% (#9132)

The goal of this change is to reduce the defrag we do to the minimal, we
want to avoid at all cost unneeded defrag causing API server request to
fail. After monitoring for few hours, I see that we still trigger
unneeded defrag so push the limit to 75%, which is 5% below etcd shield
threshold.

Signed-off-by: Hugo Ares <[email protected]>

Author: hugares

configs/etcd-defrag/production/base/cronjob.yaml

@@ -23,7 +23,7 @@ spec:
               - name: FRAGMENTATION_THRESHOLD
                 value: "30"
               - name: DISK_USAGE_THRESHOLD
-                value: "70" # lower threshold of etcd-shield
+                value: "75" # threshold of etcd-shield is 80% so we only defrag if we get close to that
               - name: RECLAIM_SPACE_THRESHOLD
                 value: "1024"
               command: