Amazon SSM Agent - Release 3.0.502.0 - 2020-12-14

• Add agent version flag to retrieve agent version
• Add onFailure/onSuccess/finallyStep support for plugins
• Add SSE header for S3 Upload
• Add SSM Agent support in MacOS
• Extend use of default http transport
• Fix for Agent not aquiring new instance role credentials after EC2 hibernation
• Fix for shell profile powershell commands not being executed in the expected order
• Fix to delete undeleted channel while using reboot document
• Fix to consider status of all plugin steps in document after system restart
• Fix bug capturing rpm install exit code
• Handle sourceInfo json sent from CLI in downloadContent plugin
• Optimize agent startup time by removing additional wait times
• Refactor makefile
• Replace master branch with mainline branch
• Upgrade aws-sdk-go to latest version(v1.35.23)