`AWS_ENDPOINT_URL` overrides the endpoint URL of aws command

[yoshizawa56]

With the recent release of AWS CLI (v1.29.0 and v2.13.0), the environment variable AWS_ENDPOINT_URL is now being referenced by the aws commands as well. This release has caused a bug where setting AWS_ENDPOINT_URL to the endpoint of LocalStack results in the aws commands connecting to LocalStack instead.

I believe it is necessary to change the name of the environment variable used for awslocal.

https://github.com/aws/aws-cli/blob/develop/CHANGELOG.rst#L29