Add support for retrieving a containerid from ECS and Fargate containers

[nrcventura]

Describe the story, please be clear on scope of the story.

There does not appear to be any container information available on the filesystem for the agent to find when an application is running in ECS or Fargate. The infra/OHI side of monitoring ECS and Fargate retrieve this information by using the AWS Task Metadata APIs. The DockerID returned by those APIs represent the container id.

If the agent supports looking for the container id using this API then it will be possible to link the infra/OHI data to the APM data.

Acceptance Criteria

• The agent supports collecting container id information for ECS and Fargate
• The collection of this information will respect the setting for disabling AWS vendor/utilization checks

Dependencies

• Dependencies on AgentSpec changes to document and standardize this behavior

Describe Design Consideration/Limitations

As part of this work, there should be code or documentation put in place to handle the case where the container id can come from multiple locations (such as the AWS utilization checks and the docker checks).

Estimates

Initial t-shirt size: S

[workato-integration]

https://new-relic.atlassian.net/browse/NR-248379