[CELEBORN-2256] Helm chart: add support for setting annotations on the service account (to support eks.amazonaws.com/role-arn)

### What changes were proposed in this pull request?
Adding support for setting "annotations" on the Celeborn Service Account.

Patch originally contributed by Filip Darmanovic Dzeri96

### Why are the changes needed?
This is needed to support AWS IAM roles in k8s EKS

### Does this PR resolve a correctness bug?

No

### Does this PR introduce _any_ user-facing change?

Yes, you can now configure the annotations.

### How was this patch tested?

Manual testing + unit tests

Closes apache#3595 from eolivelli/CELEBORN-2256.

Authored-by: Enrico Olivelli <eolivelli@gmail.com>
Signed-off-by: SteNicholas <programgeek@163.com>

Author: eolivelli

charts/celeborn/templates/serviceaccount.yaml

@@ -23,5 +23,9 @@ metadata:
   namespace: {{ .Release.Namespace }}
   labels:
     {{- include "celeborn.labels" . | nindent 4 }}
+  annotations:
+    {{- with .Values.serviceAccount.annotations }}
+    {{- toYaml . | nindent 4 }}
+    {{- end }}
 {{- end }}
 

charts/celeborn/tests/serviceaccount_test.yaml

@@ -55,3 +55,17 @@ tests:
           kind: ServiceAccount
           name: test-service-account
           namespace: celeborn
+
+  - it: Should create service account with the specified annotations
+    set:
+      serviceAccount:
+        create: true
+        name: test-service-account
+        annotations:
+          eks.amazonaws.com/role-arn: arn:aws:iam::000000:role/Foo
+    asserts:
+      - equal:
+          path: metadata.annotations
+          value:
+            eks.amazonaws.com/role-arn: arn:aws:iam::000000:role/Foo
+        template: serviceaccount.yaml

charts/celeborn/values.yaml

@@ -405,6 +405,8 @@ serviceAccount:
   create: false
   # -- (Optional) Name of the Celeborn service account.
   name: ""
+  # -- (Optional) Additional annotations, example: eks.amazonaws.com/role-arn:  arn:aws:iam::0000000000:role/XXXXXXX
+  annotations: {}
 
 rbac:
   create: true