fix env var substitution logic by parametrization (#366)

* fix env var substitution logic by parametrization

* Fix YAML syntax for chat model value

* Fix YAML syntax for AZURE_AI_MODEL_DEPLOYMENT_NAME

* Fix YAML syntax for AZURE_AI_MODEL_DEPLOYMENT_NAME

Author: jfomhover

samples/microsoft/python/getting-started-agents/hosted-agents/calculator-agent/agent.yaml

@@ -20,6 +20,10 @@ template:
       value: 2025-03-01-preview
     - name: APPLICATIONINSIGHTS_CONNECTION_STRING
       value: ${APPLICATIONINSIGHTS_CONNECTION_STRING}
+    - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
+      value: "{{chat}}"
 resources:
   - kind: model
     id: gpt-4o-mini
+    name: chat
+

samples/microsoft/python/getting-started-agents/hosted-agents/msft-docs-agent/agent.yaml

@@ -16,7 +16,9 @@ template:
     - name: AZURE_AI_PROJECT_ENDPOINT
       value: ${AZURE_AI_PROJECT_ENDPOINT}
     - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
-      value: "gpt-4o-mini"
+      value: "{{chat}}"
 resources:
   - kind: model
     id: gpt-4o-mini
+    name: chat
+  

samples/microsoft/python/getting-started-agents/hosted-agents/web-search-agent/agent.yaml

@@ -24,9 +24,10 @@ template:
     - name: BING_GROUNDING_CONNECTION_NAME
       value: ${BING_GROUNDING_CONNECTION_NAME}
     - name: AZURE_AI_MODEL_DEPLOYMENT_NAME
-      value: "gpt-4o-mini"
+      value: "{{chat}}"
 resources:
   - kind: model
     id: gpt-4o-mini
+    name: chat
   - kind: tool
     id: bing_grounding