[Tests] use libtester for detectTestDockerAgent

Issue Resolved:
#1758

Signed-off-by: Kawika Avilla <kavilla414@gmail.com>

tests/jenkins/TestDetectTestDockerAgent.groovy

@@ -15,6 +15,9 @@ class TestDetectTestDockerAgent extends BuildPipelineTest {
 
     @Test
     public void test() {
+        this.registerLibTester(new DetectTestDockerAgentLibTester(
+            'tests/jenkins/data/opensearch-1.3.0-test.yml'
+        ))
         super.testPipeline("tests/jenkins/jobs/DetectTestDockerAgent_Jenkinsfile")
     }
 }

tests/jenkins/lib-testers/DetectTestDockerAgentLibTester.groovy

@@ -0,0 +1,28 @@
+import static org.hamcrest.CoreMatchers.notNullValue
+import static org.hamcrest.MatcherAssert.assertThat
+
+
+class DetectTestDockerAgentLibTester extends LibFunctionTester {
+
+    private String testManifest
+
+    public DetectTestDockerAgentLibTester(testManifest){
+        this.testManifest = testManifest
+    }
+
+    void configure(helper, binding) {
+        // N/A
+    }
+
+    void parameterInvariantsAssertions(call) {
+        assertThat(call.args.testManifest.first(), notNullValue())
+    }
+
+    boolean expectedParametersMatcher(call) {
+        return call.args.testManifest.first().toString().equals(this.testManifest)
+    }
+
+    String libFunctionName() {
+        return 'detectTestDockerAgent'
+    }
+}