[Java] Add Performance Testing Workflow for Lambda Layer

[liustve]

Issue description:

• Added a workflow to automatically performance test and gather the results for the unreleased Java Lambda Layer.

The GitHub workflow does the following:

1. Deploy and setup the Java Lambda sample application instrumented with the Application Signals Lambda Layer on the AppSignals e2e testing aws account.
2. Record the start time of the test and run the specified amount (default: 20) Lambda cold start iterations on the sample application
3. Record the end time of the test
4. Query CW Logs Insights for the aggregated performance testing metrics with the following query:

fields @timestamp, @message, @initDuration
| filter @message like "REPORT RequestId"
| stats
    count(@initDuration) as Sample_Count,
    avg(@initDuration) as Average_Init_Duration,
    min(@initDuration) as Min_Init_Duration,
    max(@initDuration) as Max_Init_Duration,
    pct(@initDuration, 50) as P50_Init_Duration,
    pct(@initDuration, 90) as P90_Init_Duration,
    pct(@initDuration, 99) as P99_Init_Duration'

5. Parse and flatten the result from the query call and save it in a file.
6. Clean and destroy the deployed lambda resources upon completion, cancellation, or failure.

Testing
Testing was done on a personal aws dev account with the exact IAM permissions as the e2e testing aws account.
Example of a successful job:

https://github.com/liustve/aws-application-signals-test-framework/actions/runs/14392326689