boto3 invoke method can not be instrumented

In case of lambda function invoking other function there is a problem with instrumentation of the invoke() method.

Describe your environment

• https://github.com/open-telemetry/opentelemetry-lambda/tree/main/python
• AWS Lambda Python 3.8 runtime
• opentelemetry-instrumentation 0.24b0 (tested also on 0.25b2)
• opentelemetry-instrumentation-boto 0.24b0 (tested also on 0.25b2)
• opentelemetry-instrumentation-botocore 0.24b0 (tested also on 0.25b2)
• boto3 - tested on various versions, gives the same result

Steps to reproduce
Create two AWS Lambda functions - A and B. Function A by boto3.invoke() function B.
Please see example code in the Additional context

What is the expected behavior?
I expect correct instrumentation of the boto3 invoke method and valid headers.

What is the actual behavior?

[ERROR] AttributeError: 'str' object has no attribute 'get'
Traceback (most recent call last):
  File "/opt/python/opentelemetry/instrumentation/aws_lambda/__init__.py", line 222, in _instrumented_lambda_handler_call
    result = call_wrapped(*args, **kwargs)
  File "/var/task/check_sweets.py", line 24, in get_sweets
    response = invoke(body)
  File "/var/task/check_sweets.py", line 12, in invoke
    response = client.invoke(
  File "/var/task/botocore/client.py", line 386, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/opt/python/opentelemetry/instrumentation/botocore/__init__.py", line 215, in _patched_api_call
    BotocoreInstrumentor._patch_lambda_invoke(call_context.params)
  File "/opt/python/opentelemetry/instrumentation/botocore/__init__.py", line 178, in _patch_lambda_invoke
    headers = payload.get("headers", 
{}
)

Additional context
example code

import json
import os
import boto3

FUNCTION_NAME = os.getenv('INVOKE_FUNCTION_NAME')

client = boto3.client('lambda')


def invoke(sweets):
    print('Invoke %s with data: %s' % (FUNCTION_NAME, sweets))
    response = client.invoke(
        FunctionName=FUNCTION_NAME,
        InvocationType='RequestResponse',
        Payload=json.dumps(sweets),
    )
    return response


def get_sweets(event, context):
    body = event['body']

    print('Check if %s is available' % str(body))
    response = invoke(body)
    payload = json.loads(response["Payload"].read())

    return {'statusCode': payload['statusCode'], 'body': json.dumps(payload['body'])}

Note
The same issue created under https://github.com/open-telemetry/opentelemetry-lambda/issues/166

Start with opentelemetry/instrumentation/botocore/init.py, especially _patched_api_call and _patch_lambda_invoke, and compare the reported Payload value with the expected structure. Reproduce the AWS Lambda-to-Lambda boto3 invoke example and verify that instrumentation completes without AttributeError and produces valid headers; check the referenced duplicate issue 166 for current status.