Fix env var interpolation in Azure CLI commands.

Author: v-jaswel

articles/container-apps/managed-identity-image-pull.md

@@ -384,10 +384,10 @@ New-AzUserAssignedIdentity -Name $IdentityName -ResourceGroupName $ResourceGroup
 Get identity's resource ID.
 
 ```azurecli
-IDENTITY_ID=`az identity show \
+IDENTITY_ID=$(az identity show \
   --name $IDENTITY \
   --resource-group $RESOURCE_GROUP \
-  --query id`
+  --query id)
 ```
 
 # [Azure PowerShell](#tab/azure-powershell)
@@ -432,8 +432,8 @@ az containerapp create \
   --environment $CONTAINERAPPS_ENVIRONMENT \
   --user-assigned <IDENTITY_ID> \
   --registry-identity <IDENTITY_ID> \
-  --registry-server "$REGISTRY_NAME.azurecr.io" \
-  --image "$REGISTRY_NAME.azurecr.io/$IMAGE_NAME:latest"
+  --registry-server "${REGISTRY_NAME}.azurecr.io" \
+  --image "${REGISTRY_NAME}.azurecr.io/${IMAGE_NAME}:latest"
 ```
 
 # [Azure PowerShell](#tab/azure-powershell)
@@ -550,14 +550,14 @@ az containerapp registry set \
   --name $CONTAINERAPP_NAME \
   --resource-group $RESOURCE_GROUP \
   --identity system \
-  --server "$REGISTRY_NAME.azurecr.io"
+  --server "${REGISTRY_NAME}.azurecr.io"
 ```
 
 ```azurecli
 az containerapp update \
   --name $CONTAINERAPP_NAME \
   --resource-group $RESOURCE_GROUP \
-  --image "$REGISTRY_NAME.azurecr.io/$IMAGE_NAME:latest"
+  --image "${REGISTRY_NAME}.azurecr.io/${IMAGE_NAME}:latest"
 ```
 
 # [Azure PowerShell](#tab/azure-powershell)
@@ -815,8 +815,8 @@ Deploy your container app with the following command.
 
 ```azurecli
 az deployment group create \
-  --resource-group "$RESOURCE_GROUP" \
-  --template-file "$BICEP_TEMPLATE" \
+  --resource-group $RESOURCE_GROUP \
+  --template-file $BICEP_TEMPLATE \
   --parameters environmentName="$CONTAINERAPPS_ENVIRONMENT" \
   logAnalyticsWorkspaceName="$LOG_ANALYTICS_WORKSPACE_NAME" \
   appInsightsName="$APP_INSIGHTS_NAME" \