diagnostics:probeImage is a required field otherwise the frontend fails to pass healthchecks.

Author: ryanwinter

articles/iot-operations/manage-mqtt-connectivity/howto-configure-availability-scale.md

@@ -126,6 +126,8 @@ spec:
     pullPolicy: Always
     repository: mcr.microsoft.com/azureiotoperations/dmqtt-operator
     tag: 0.4.0-preview
+  diagnostics:
+    probeImage: mcr.microsoft.com/azureiotoperations/diagnostics-probe:0.4.0-preview
   memoryProfile: medium
   mode: distributed
   cardinality: