bug: Properly parameterize zookeeper-client-tls everywhere

In some cases we were using a secret named zookeeper-client-tls, in
some cases we were using the secret from the Zuul specification.
Having a magic name for the secret doesn't make sense and we should
instead just use the parameterization everywhere.

Change-Id: I4027ef2a8edae99e50e6c73fe2426ca6d6bc677b

zuul_operator/templates/nodepool-launcher.yaml

@@ -50,7 +50,7 @@ spec:
           secretName: {{ nodepool_config_secret_name }}
       - name: zookeeper-client-tls
         secret:
-          secretName: {{ instance_name }}-zookeeper-client-tls
+          secretName: {{ spec.zookeeper.secretName }}
       {%- for name, c in external_config.items() %}
       - name: {{ name }}
         secret:

zuul_operator/templates/zuul.yaml

@@ -194,7 +194,7 @@ spec:
           secretName: {{ zuul_tenant_secret }}
       - name: zookeeper-client-tls
         secret:
-          secretName: {{ instance_name }}-zookeeper-client-tls
+          secretName: {{ spec.zookeeper.secretName }}
       {%- for connection_name, connection in connections.items() %}
       {%- if 'secretName' in connection %}
       - name: connection-{{ connection_name }}
@@ -262,7 +262,7 @@ spec:
           secretName: {{ instance_name }}-zuul-config
       - name: zookeeper-client-tls
         secret:
-          secretName: {{ instance_name }}-zookeeper-client-tls
+          secretName: {{ spec.zookeeper.secretName }}
 ---
 apiVersion: apps/v1
 kind: Deployment
@@ -310,7 +310,7 @@ spec:
           secretName: {{ instance_name }}-zuul-config
       - name: zookeeper-client-tls
         secret:
-          secretName: {{ instance_name }}-zookeeper-client-tls
+          secretName: {{ spec.zookeeper.secretName }}
 ---
 apiVersion: apps/v1
 kind: StatefulSet