fix(aws-glue-alpha): address PR review feedback for metrics control

- Fix JSDoc @default comments to be drop-in values without explanatory text
- Improve README example by removing redundant enableObservabilityMetrics line
- Enhance integration test with AwsSdkCall assertions to validate actual job configurations
- Add comprehensive API-level validation that metrics arguments are correctly included/excluded

Addresses review feedback from @iankhou on PR #35154:
- JSDoc @default values now follow CDK conventions
- README example is cleaner and more accurate
- Integration test now validates real AWS API responses instead of just deployment
- Added assertions to verify --enable-metrics and --enable-observability-metrics
  arguments are properly handled in job DefaultArguments

The enhanced integration test uses awsApiCall('Glue', 'getJob') to validate:
- Jobs with disabled metrics don't have metrics arguments
- Jobs with selective control have correct argument combinations
- Default behavior maintains backward compatibility

Author: pahud

packages/@aws-cdk/aws-glue-alpha/README.md

@@ -367,7 +367,7 @@ new glue.PySparkEtlJob(stack, 'SelectiveJob', {
   role,
   script,
   enableMetrics: false,
-  enableObservabilityMetrics: true,
+  // enableObservabilityMetrics defaults to true
 });
 ```
 

packages/@aws-cdk/aws-glue-alpha/lib/jobs/ray-job.ts

@@ -35,7 +35,7 @@ export interface RayJobProps extends JobProps {
    *
    * When enabled, adds '--enable-metrics' to job arguments.
    *
-   * @default true - metrics are enabled by default for backward compatibility
+   * @default true
    */
   readonly enableMetrics?: boolean;
 
@@ -44,7 +44,7 @@ export interface RayJobProps extends JobProps {
    *
    * When enabled, adds '--enable-observability-metrics': 'true' to job arguments.
    *
-   * @default true - observability metrics are enabled by default for backward compatibility
+   * @default true
    */
   readonly enableObservabilityMetrics?: boolean;
 }

packages/@aws-cdk/aws-glue-alpha/lib/jobs/spark-job.ts

@@ -107,7 +107,7 @@ export interface SparkJobProps extends JobProps {
    *
    * When enabled, adds '--enable-metrics' to job arguments.
    *
-   * @default true - metrics are enabled by default for backward compatibility
+   * @default true
    */
   readonly enableMetrics?: boolean;
 
@@ -116,7 +116,7 @@ export interface SparkJobProps extends JobProps {
    *
    * When enabled, adds '--enable-observability-metrics': 'true' to job arguments.
    *
-   * @default true - observability metrics are enabled by default for backward compatibility
+   * @default true
    */
   readonly enableObservabilityMetrics?: boolean;
 }