Fix argument extraction for AWS Bedrock tool calls in
_parse_native_tool_call. The old code used
func_info.get('arguments', '{}') which always returns the truthy
string '{}', preventing the 'or' fallback from ever reaching
tool_call.get('input', {}). This caused all Bedrock tool calls to
receive empty arguments regardless of what the LLM provides.
Changed to func_info.get('arguments') or tool_call.get('input') or {}
which correctly falls through to the Bedrock 'input' field when
'arguments' is not present.
Fixes#4748
Co-Authored-By: João <joao@crewai.com>
9900a79546