[BugFix] Fix unintended parsing tool calls

[16oeahr]

Description

Fix unintended parsing tool calls

Error: Use GPT Function Calling-04-25-2024-12-19-14 - Azure AI | Machine Learning Studio

Same experiment run success after fix:
https://ml.azure.com/prompts/flow/f8925d22-478a-4b5c-8e16-a85158d03b9b/cd75a85c-33d5-4348-8e8c-ed6fc392c3b4/details?wsid=/subscriptions/96aede12-2f73-41cb-b983-6d11a904839b/resourceGroups/promptflow/providers/Microsoft.MachineLearningServices/workspaces/promptflow-eastus-dev&tid=72f988bf-86f1-41af-91ab-2d7cd011db47

Run tool sample with fix:
https://ml.azure.com/prompts/flow/f8925d22-478a-4b5c-8e16-a85158d03b9b/3e2c30b8-d41e-4114-adb3-0f180fcbc6fe/details?wsid=/subscriptions/96aede12-2f73-41cb-b983-6d11a904839b/resourcegroups/promptflow/providers/Microsoft.MachineLearningServices/workspaces/promptflow-eastus-dev&flight=pfnewllm,pfflowleveltool&tid=72f988bf-86f1-41af-91ab-2d7cd011db47

All Promptflow Contribution checklist:

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