fix: imageurl without quotes

[krishnaGajabi]

Issue:
image url containing {{ }} is being interpreted as a function on mayastor helm chart
Root Cause:
image url being rendered using tpl which treats it as helm function
Steps to Reproduce:
values.yaml

global:
  imageRegistry: "{{ my_registry }}/my-org/"

Command :
helm template chartsdirectory -f values.yaml

Error:
`Error: template: mayastor/templates/mayastor/agents/ha/ha-node-daemonset.yaml:31:12: executing "mayastor/templates/mayastor/agents/ha/ha-node-daemonset.yaml" at <include "base_init_ha_node_containers" .>: error calling include: template: mayastor/templates/_helpers.tpl:34:8: executing "base_init_ha_node_containers" at <include "render_init_containers" (dict "value" .Values.base.initHaNodeContainers.containers "context" $)>: error calling include: template: mayastor/templates/_helpers.tpl:405:8: executing "render_init_containers" at <tpl ($containers | toYaml) .context>: error calling tpl: cannot parse template "- command:\n - sh\n - -c\n - trap "exit 1" TERM; until nc -vzw 5 {{ .Release.Name }}-agent-core 50052; do date;\n echo "Waiting for agent-cluster-grpc services..."; sleep 1; done;\n image: '{{ my_registry }}/my-org//openebs/alpine-sh:4.5.0'\n imagePullPolicy: IfNotPresent\n name: agent-cluster-grpc-probe": template: gotpl:6: function "my_registry" not defined

Use --debug flag to render out invalid YAML
(END)`

Solution:
Only render the initcontainer command with tpl and eveyrthing else wihout it.

This PR also fixes preupgrade hook image url which had no quotes in previous versions.

[Copilot]

Pull request overview

Fixes Helm rendering failures when an image registry contains {{ ... }} by avoiding tpl evaluation of initContainer YAML (which previously interpreted those braces as Go template functions), and aligns the pre-upgrade hook image field formatting with the rest of the chart.

Changes:

• Quote the pre-upgrade hook image: value so rendered YAML remains valid even when registry strings contain {/}.
• Update render_init_containers to render only command entries via tpl while emitting the rest of the container YAML without tpl, preventing accidental template evaluation of image strings.
• Factor default initContainer image construction into a dedicated render_init_container_image helper.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
chart/templates/pre-upgrade-hook.yaml	Quotes the pre-upgrade hook image string to avoid invalid YAML when registry values contain special characters.
chart/templates/_helpers.tpl	Stops tpl-rendering the full initContainer YAML; selectively tpl-renders command only and centralizes default initContainer image generation.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[tiagolobocastro]

I think this is ok since only the command needs templating?
@niladrih