Remove usage of aws-appsignals-sample-app-prod (#398)

[thpierce]

Issue description:

We have a hard dependency on the aws-appsignals-sample-app-prod-region bucket, which made running anything in personal repos impossible.

Description of changes:
Replace all references to bucket with input (with default). Also disables fail-fast in traffic-generator-image-build.yml, which was another thing that would fail in personal repos.

Rollback procedure:

Simple revert.

Ensure you've run the following tests on your changes and include the link below:

Tested:

• dotnet-sample-app-s3-deploy.yml - https://github.com/thpierce/aws-application-signals-test-framework/actions/runs/14917895356 (only passes in us-east-1, because I only created that bucket)
• ava-sample-app-s3-deploy.yml - https://github.com/thpierce/aws-application-signals-test-framework/actions/runs/14916546220 (only passes in us-east-1, because I only created that bucket)
• traffic-generator-image-build.yml - https://github.com/thpierce/aws-application-signals-test-framework/actions/runs/14917895356 (only passes in us-east-1, because I only created that bucket)
• https://github.com/aws/amazon-cloudwatch-agent/actions/runs/14918129559
  • java-ec2-default-test.yml
  • java-ec2-asg-test.yml
  • java-k8s-test.yml
  • python-ec2-default-test.yml
  • python-ec2-asg-test.yml
  • python-k8s-test.yml
  • node-ec2-default-test.yml
  • node-ec2-asg-test.yml
  • node-k8s-test.yml
  • dotnet-ec2-default-test.yml
  • dotnet-ec2-windows-test.yml
  • dotnet-k8s-test.yml
• dotnet-ec2-adot-sigv4-test.yml - PENDING
• dotnet-ec2-asg-test.yml - PENDING
• dotnet-ec2-nuget-test.yml - PENDING
• dotnet-lambda-test.yml - PENDING
• java-ec2-adot-sigv4-test.yml - PENDING
• java-ec2-ubuntu-test.yml - PENDING
• java-lambda-test.yml - PENDING
• node-ec2-adot-sigv4-test.yml - PENDING
• node-lambda-test.yml - PENDING
• python-ec2-adot-sigv4-test.yml - PENDING
• python-lambda-test.yml - PENDING

Not tested (not impacted by changes)

• Unrelated workflows/no relevant S3 usage:
  • appsignals-e2e-gamma-test.yml
  • dummy-k8s-test.yml
  • enablement-test-publish-result.yml
  • k8s-patch-os-jobs.yml
  • k8s-patch-os-matrix.yml
  • pr-build.yml
• EKS/ECR tests don't use S3 bucket:
  • dotnet-eks-test.yml
  • dotnet-eks-windows-test.yml
  • dotnet-sample-app-ecr-deploy.yml
  • java-ecs-test.yml
  • java-eks-otlp-ocb-canary.yml
  • java-eks-otlp-ocb-retry.yml
  • java-eks-otlp-ocb-test.yml
  • java-eks-test.yml
  • java-sample-app-ecr-deploy.yml
  • node-ecs-test.yml
  • node-eks-test.yml
  • metric-limiter-test.yml
  • node-sample-app-ecr-deploy.yml
  • python-ecs-test.yml
  • python-eks-test.yml
  • python-sample-app-ecr-deploy.yml
• Lambda perf tests don't use S3 bucket:
  • dotnet-lambda-layer-perf-test.yml
  • java-lambda-layer-perf-test.yml
  • node-lambda-layer-perf-test.yml
  • python-lambda-layer-perf-test.yml
• Uses a different S3 bucket (or possibly the same? Need to look at secret val)
  • node-sample-app-s3-deploy.yml
  • python-sample-app-s3-deploy.yml
  • resource-cleanup.yml

NOTE: TESTS RUNNING ON A SINGLE EKS CLUSTER CANNOT BE RUN IN PARALLEL. See the needs keyword to run tests in succession.

• Run Java EKS on e2e-playground in us-east-1 and eu-central-2
• Run Python EKS on e2e-playground in us-east-1 and eu-central-2
• Run metric limiter on EKS cluster e2e-playground in us-east-1 and eu-central-2
• Run EC2 tests in all regions
• Run K8s on a separate K8s cluster (check IAD test account for master node endpoints; these will change as we create and destroy clusters for OS patching)

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.