[core] support S3 path style access in runtime_env download_and_unpack_package()

[hongchaodeng]

Description

Currently, when we use runtime_env to download and unpack packages from S3 compatible storage, it might use path style access.

However, the current S3 client code didn't support that. It needs to specify addressing_style config:

boto3.client('s3', 'us-west-2', config=Config(s3={'addressing_style': 'path'}))

Use case

No response

[hongchaodeng]

Closing this since boto client can be configured via ~/.aws/config file:

https://boto3.amazonaws.com/v1/documentation/api/1.14.23/guide/configuration.html