[Java] SigV4 logs release testing

[Jeel-mehta]

Issue description:
This PR implements and validates SigV4 log functionality for Java EC2 ADOT (Stand-Alone ADOT) use case. The implementation focuses on validating logs sent to the otlp_logs log group, ensuring a consistent and reliable validation approach that can be replicated across different language implementations.

Description of changes:

1. Updated Terraform configuration:

• Added OTLP logs exporter configuration
• Updated environment variables for SigV4 authentication

2. Added validation resources:

• Created new log.mustache template for SigV4 logs validation
• Added log-validation.yml configuration
• Updated PredefinedExpectedTemplate.java to include SigV4 logs template
• Modified CWLogValidator.java to support SigV4 logs validation

3. Workflow Updates:

• Added new validation step for SigV4 logs
• Configured TEST_LOG_GROUP_NAME environment variable

Rollback procedure:

1. Reverting the Terraform configuration changes
2. Removing the added validation files and code changes
3. Removing the SigV4 logs validation step from the workflow

Test run- For Java https://github.com/aws-observability/aws-application-signals-test-framework/actions/runs/15501714651
Also Validating for Python https://github.com/aws-observability/aws-application-signals-test-framework/actions/runs/15450029203 as the filter pattern was changed in the CWLogValidator.java

<Can we safely revert this commit if needed? If not, detail what must be done to safely revert and why it is needed.>

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

To do so, create a test.yml file with name: Test and workflow description to test your changes, then remove the file for your PR. Link your test run in your PR description. This process is a short term solution while we work on creating a staging environment for testing.

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.