feat(pod): add switch to enable checksum annotation

Depending on the environment or tooling in which the chart is deployed, you may
or may not want to have the checksum annotation.

In the past, these were enforced. The default remains that the checksum
annotation is added. It now only contains a switch that allows you to optionally
disable it.

unittests/deployment/downloadMode.yaml

@@ -40,6 +40,7 @@ tests:
 - it: Rendering default with mounted gitconfig configMap
   set:
     config.downloadMode.enabled: true
+    config.downloadMode.addSHASumAnnotation: true
     persistence.enabled: true
   asserts:
     - exists:
@@ -69,16 +70,87 @@ tests:
             name: athens-proxy-unittest-download-mode-file
       template: templates/deployment.yaml
 
+- it: Rendering default with mounted gitconfig configMap
+  set:
+    config.downloadMode.enabled: true
+    config.downloadMode.addSHASumAnnotation: false
+    persistence.enabled: true
+  asserts:
+    - notExists:
+        path: spec.template.metadata.annotations.checksum/config-map-athens-proxy-unittest-download-mode-file
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.containers[0].env
+        content:
+          name: ATHENS_DOWNLOAD_MODE
+          value: file:/etc/athens/config/download-mode.d/download-mode
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.containers[0].volumeMounts
+        content:
+          name: download-mode
+          mountPath: /etc/athens/config/download-mode.d
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.volumes
+        content:
+          name: download-mode
+          configMap:
+            items:
+              - key: downloadMode
+                mode: 0644
+                path: download-mode
+            name: athens-proxy-unittest-download-mode-file
+      template: templates/deployment.yaml
+
+
 - it: Rendering with custom download mode configMap
   set:
     config.downloadMode.enabled: true
+    config.downloadMode.addSHASumAnnotation: true
+    config.downloadMode.existingConfigMap.enabled: true
+    config.downloadMode.existingConfigMap.configMapName: "my-custom-configmap"
+    config.downloadMode.existingConfigMap.downloadModeKey: "my-custom-download-mode-filename-key"
+    persistence.enabled: true
+  asserts:
+    - exists:
+        path: spec.template.metadata.annotations.checksum/config-map-my-custom-configmap
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.containers[0].env
+        content:
+          name: ATHENS_DOWNLOAD_MODE
+          value: file:/etc/athens/config/download-mode.d/download-mode
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.containers[0].volumeMounts
+        content:
+          name: download-mode
+          mountPath: /etc/athens/config/download-mode.d
+      template: templates/deployment.yaml
+    - contains:
+        path: spec.template.spec.volumes
+        content:
+          name: download-mode
+          configMap:
+            items:
+            - key: "my-custom-download-mode-filename-key"
+              path: "download-mode"
+              mode: 0644
+            name: my-custom-configmap
+      template: templates/deployment.yaml
+
+- it: Rendering with custom download mode configMap, but without sha sum annotation
+  set:
+    config.downloadMode.enabled: true
+    config.downloadMode.addSHASumAnnotation: false
     config.downloadMode.existingConfigMap.enabled: true
     config.downloadMode.existingConfigMap.configMapName: "my-custom-configmap"
     config.downloadMode.existingConfigMap.downloadModeKey: "my-custom-download-mode-filename-key"
     persistence.enabled: true
   asserts:
     - notExists:
-        path: spec.template.metadata.annotations.checksum/config-map-athens-proxy-unittest-download-mode-file
+        path: spec.template.metadata.annotations.checksum/config-map-my-custom-configmap
       template: templates/deployment.yaml
     - contains:
         path: spec.template.spec.containers[0].env