[examples] rename APIGateway examples to APIGatewayV2

[sebsto]

Now that we have a APIGatewayV1 example (thank you @everyplace), we should rename the two other AIPGateway examples.

Current names -> proposed new names
Examples/APIGateway -> Examples/APIGatewayV2
Examples/APIGateway+LambdaAuthorizer -> Examples/APIGatewayV2+LambdaAuthorizer

• change the CI script