docs: move AwsLambdaInstrumentor().instrument() to after the lambda function (#3085)

Co-authored-by: Emídio Neto <9735060+emdneto@users.noreply.github.com>

Author: Kludex

instrumentation/opentelemetry-instrumentation-aws-lambda/src/opentelemetry/instrumentation/aws_lambda/__init__.py

@@ -29,7 +29,6 @@
 
     # Enable instrumentation
     BotocoreInstrumentor().instrument()
-    AwsLambdaInstrumentor().instrument()
 
     # Lambda function
     def lambda_handler(event, context):
@@ -39,6 +38,8 @@ def lambda_handler(event, context):
 
         return "200 OK"
 
+    AwsLambdaInstrumentor().instrument()
+
 API
 ---