Google: Continue on MALFORMED_FUNCTION_CALL

[ArneZsng]

Using Gemini, we are frequently running into the MALFORMED_FUNCTION_CALL as the finish reason.
Google seemingly does not provide any context in the response for the reason of the MALFORMED_FUNCTION_CALL.

In these cases, the agent can continue retrying which I why I suggest to simply continue in the case of a MALFORMED_FUNCTION_CALL.

Related to #631

The issue is most prevalent when using Gemini 2.5 Flash (compared to Gemini 2.5 Pro where it also happens but less frequently).

Example chunk:

sdk_http_response=HttpResponse(
  headers=<dict len=11>
) candidates=[Candidate(
  finish_reason=<FinishReason.MALFORMED_FUNCTION_CALL: 'MALFORMED_FUNCTION_CALL'>,
  index=0
)] create_time=None model_version=None prompt_feedback=None response_id=None usage_metadata=GenerateContentResponseUsageMetadata(
  prompt_token_count=2595,
  prompt_tokens_details=[
    ModalityTokenCount(
      modality=<MediaModality.TEXT: 'TEXT'>,
      token_count=2595
    ),
  ],
  total_token_count=2595
) automatic_function_calling_history=None parsed=None