Kotlin - Testing: Remove Credential override

[ford prior]

For all 27 tests that override credentials, remove custom config and allow test to use Batch role credentials.

Example of failure:

1710804060651, APIGatewayTest > initializationError FAILED
1710804060652,     aws.sdk.kotlin.runtime.auth.credentials.ProviderConfigurationException at APIGatewayTest.kt:98

Files with error:

• APIGatewayTest (APIGatewayTest.kt:98)
• AppSyncTest (AppSyncTest.kt:116)
• AthenaTest (AthenaTest.kt:103)
• AutoScalingTest (AutoScalingTest.kt:139)
• CloudFormationTest (CloudFormationTest.kt:89)
• CloudTrailKotlinTest (CloudtrailKotlinTest.kt:108)
• CloudWatchTest (CloudWatchTest.kt:207)
• PipelineServiceTest (PipelineServiceTest.kt:93)
• CognitoKotlinTest (CognitoKotlinTest.kt:205)
• ComprehendKotlinTest (ComprehendKotlinTest.kt:101)
• DynamoDBTest (DynamoDB.kt:227)
• EC2Test (EC2Test.kt:350)
• ESCTest (ESCTest.kt:126)
• KendraTest (KendraTest.kt:139)
• KMSKotlinTest (KMSKotlinTest.kt:161)
• LambdaTest (LambdaTest.kt:142)
• LexTest (LexTest.kt:98)
• MCTest (MCTest.kt:81)
• PersonalizeKotlinTest (PersonalizeKotlinTest.kt:158)
• PinpointKotlinTest (PinpointKotlinTest.kt:179)
• PollyKotlinTest (PollyKotlinTest.kt:20)
• RDSTest (RDSTest.kt:58)
• RekognitionTest (RekognitionTest.kt:218)
• Route53Test (Route53Test.kt:182)