type: "enum", values: [...] is not accepted

[LaKing]

Description of the bug:

According to the documentation at https://ai.google.dev/gemini-api/docs/function-calling

Best practices for function declarations
...
properties > type: Use strongly typed parameters to reduce model hallucinations. For example, if the parameter values are from a finite set, use an enum field instead of listing the values in the description (e.g., "type": "enum", "values": ["now_playing", "upcoming"]). If the parameter value is always an integer, set the type to integer rather than number.
...

However, using the "enum" type with a values array sent, results in errors.
Error: [GoogleGenerativeAI Error]: Error fetching from https://generativelanguage.googleapis.com/v1beta/models/gemini-2.0-flash-exp:streamGenerateContent?alt=sse: [400 Bad Request] Invalid value at 'tools.function_declarations[1].parameters.properties[1].value.type' (type.googleapis.com/google.ai.generativelanguage.v1beta.Type), "enum"

Invalid value at 'tools.function_declarations[2].parameters.properties[1].value.type' (type.googleapis.com/google.ai.generativelanguage.v1beta.Type), "enum"
Invalid JSON payload received. Unknown name "values" at 'tools.function_declarations[2].parameters.properties[1].value': Cannot find field.