fix(e2e): add enableDeltaXDS configuration to values.yaml and update controller-deployment.yaml to include ISTIO_DELTA_XDS environment variable

Change-Id: I2e938e85b7908a3a82c57abfee47589ea69c334a
Co-developed-by: Cursor <noreply@cursor.com>

helm/core/templates/controller-deployment.yaml

@@ -173,6 +173,8 @@ spec:
             value: "{{ .Values.global.xdsMaxRecvMsgSize }}"
           - name: ENBALE_SCOPED_RDS
             value: "{{ .Values.global.enableSRDS }}"
+          - name: ISTIO_DELTA_XDS
+            value: "{{ .Values.global.enableDeltaXDS }}"
           - name: ON_DEMAND_RDS
             value: "{{ .Values.global.onDemandRDS }}"
           - name: HOST_RDS_MERGE_SUBSET

helm/core/values.yaml

@@ -9,6 +9,8 @@ global:
   xdsMaxRecvMsgSize: "104857600"
   defaultUpstreamConcurrencyThreshold: 10000
   enableSRDS: true
+  # -- Whether to enable Istio delta xDS. Default is false due to SRDS compatibility.
+  enableDeltaXDS: false
   # -- Whether to enable Redis(redis-stack-server) for Higress, default is false.
   enableRedis: false
   enablePluginServer: false