[filebeat][awss3][automation] Panic in integration test while polling input metrics for SQS

[bhapas]

While working on a fix - #36054 for the skipped integration tests for awss3 input integration test , it has been found that

• There is a panic error when trying to poll sqsMessagesWaiting metric

https://beats-ci.elastic.co/job/Beats/job/beats/job/PR-36054/21/consoleText

[2023-07-14T13:46:26.042Z] {"log.level":"info","@timestamp":"2023-07-14T13:46:25.818Z","log.logger":"metric_registry","log.origin":{"file.name":"inputmon/input.go","file.line":70},"message":"unregistering","input_type":"aws-s3","id":"test_id","key":"test_id","uuid":"d281d8ad-006a-42e6-8a19-8fcae03d7b2c","ecs.version":"1.6.0"}
[2023-07-14T13:46:26.042Z] panic: runtime error: invalid memory address or nil pointer dereference [recovered]
[2023-07-14T13:46:26.042Z] 	panic: runtime error: invalid memory address or nil pointer dereference
[2023-07-14T13:46:26.042Z] [signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x33e69fb]
[2023-07-14T13:46:26.042Z] 
[2023-07-14T13:46:26.042Z] goroutine 248962 [running]:
[2023-07-14T13:46:26.042Z] testing.tRunner.func1.2({0x3755600, 0x564e4b0})
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/.gvm/versions/go1.19.10.linux.amd64/src/testing/testing.go:1396 +0x24e
[2023-07-14T13:46:26.042Z] testing.tRunner.func1()
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/.gvm/versions/go1.19.10.linux.amd64/src/testing/testing.go:1399 +0x39f
[2023-07-14T13:46:26.042Z] panic({0x3755600, 0x564e4b0})
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/.gvm/versions/go1.19.10.linux.amd64/src/runtime/panic.go:884 +0x212
[2023-07-14T13:46:26.042Z] github.com/elastic/elastic-agent-libs/monitoring.(*Int).Get(...)
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/pkg/mod/github.com/elastic/elastic-agent-libs@v0.3.9/monitoring/metrics.go:64
[2023-07-14T13:46:26.042Z] github.com/elastic/beats/v7/x-pack/filebeat/input/awss3.TestInputRunSNS(0xc000fc8b60)
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/src/github.com/elastic/beats/x-pack/filebeat/input/awss3/input_integration_test.go:430 +0x5bb
[2023-07-14T13:46:26.042Z] testing.tRunner(0xc000fc8b60, 0x3ce7058)
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/.gvm/versions/go1.19.10.linux.amd64/src/testing/testing.go:1446 +0x10b
[2023-07-14T13:46:26.042Z] created by testing.(*T).Run
[2023-07-14T13:46:26.042Z] 	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/.gvm/versions/go1.19.10.linux.amd64/src/testing/testing.go:1493 +0x35f
[2023-07-14T13:46:26.042Z] 
[2023-07-14T13:46:26.042Z] DONE 1213 tests, 13 skipped, 2 failures in 151.809s
[2023-07-14T13:46:29.754Z] Error: failed to execute go: exit status 1

• When polling sqsWorkerUtilization metric , the value is always 0.

https://beats-ci.elastic.co/job/Beats/job/beats/job/PR-36054/22/consoleText

[2023-07-14T13:46:26.037Z] {"log.level":"info","@timestamp":"2023-07-14T13:45:52.963Z","log.logger":"metric_registry","log.origin":{"file.name":"inputmon/input.go","file.line":70},"message":"unregistering","input_type":"aws-s3","id":"test_id","key":"test_id","uuid":"1dd685c1-ea08-4288-8966-b209e8061e42","ecs.version":"1.6.0"}
[2023-07-14T13:46:26.037Z]     input_integration_test.go:196: 
[2023-07-14T13:46:26.037Z]         	Error Trace:	/var/lib/jenkins/workspace/PR-36054-22-6fc08257-c6b0-4bbe-ac34-b86205d2a2e8/src/github.com/elastic/beats/x-pack/filebeat/input/awss3/input_integration_test.go:196
[2023-07-14T13:46:26.037Z]         	Error:      	"0" is not greater than "0"
[2023-07-14T13:46:26.037Z]         	Test:       	TestInputRunSQS

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)