Don't pass URL to --content

[cartermckinnon]

Description of changes:

The --content flag on aws ssm create-document no longer supports http(s):// URIs on recent CLI versions.

All AWS CLI parameters support the file:// scheme, so this switches to that: https://docs.aws.amazon.com/cli/latest/userguide/cli-usage-parameters-file.html#cli-usage-parameters-file-how

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Testing Done

CLI version:

> aws --version
aws-cli/2.9.23 Python/3.9.11 Darwin/22.3.0 exe/x86_64 prompt/off

Doesn't work:

> aws ssm create-document \
>   --name "EKSLogCollectorLinux" \
>   --document-type "Command" \
>   --content https://raw.githubusercontent.com/awslabs/amazon-eks-ami/master/log-collector-script/linux/eks-ssm-content.json


An error occurred (InvalidDocumentContent) when calling the CreateDocument operation: JSON not well-formed. at Line: 1, Column: 6

Works:

> curl -O https://raw.githubusercontent.com/awslabs/amazon-eks-ami/master/log-collector-script/linux/eks-ssm-content.json
> aws ssm create-document \
>   --name "EKSLogCollectorLinux" \
>   --document-type "Command" \
>   --content file://eks-ssm-content.json