fix: update default tool call system prompt (#1712)

# What does this PR do?
closes #1584 

This should be a rather innocuous change. 

## Test Plan

Verify that there's no more tool call parsing error for example in issue
<img width="1216" alt="image"
src="https://github.com/user-attachments/assets/a5a6f4e8-2093-4ca2-bc06-794b707a0429"
/>

LLAMA_STACK_CONFIG=fireworks pytest -s -v
tests/integration/agents/test_agents.py --safety-shield
meta-llama/Llama-Guard-3-8B --text-model
meta-llama/Llama-3.1-8B-Instruct

llama_stack/models/llama/llama3/prompt_templates/system_prompts.py

@@ -244,6 +244,7 @@ class PythonListCustomToolGenerator(PromptTemplateGeneratorBase):  # noqa: N801
         template_str = textwrap.dedent(
             """
             If you decide to invoke any of the function(s), you MUST put it in the format of [func_name1(params_name1=params_value1, params_name2=params_value2...), func_name2(params)]
+            For a boolean parameter, be sure to use `True` or `False` (capitalized) for the value.
             You SHOULD NOT include any other text in the response.
 
             Here is a list of functions in JSON format that you can invoke.