Fix flaky unit tests

Author: psx95

gcp-auth-extension/build.gradle.kts

@@ -55,6 +55,9 @@ dependencies {
 tasks {
   test {
     useJUnitPlatform()
+    // Unset relevant environment variables to provide a clean state for the tests
+    environment("GOOGLE_CLOUD_PROJECT", "")
+    environment("GOOGLE_CLOUD_QUOTA_PROJECT", "")
     // exclude integration test
     exclude("io/opentelemetry/contrib/gcp/auth/GcpAuthExtensionEndToEndTest.class")
   }
@@ -127,34 +130,7 @@ tasks.register<Test>("IntegrationTestUserCreds") {
     "-Dotel.metrics.exporter=none",
     "-Dotel.logs.exporter=none",
     "-Dotel.exporter.otlp.protocol=http/protobuf",
-    "-Dmockserver.logLevel=off"
-  )
-}
-
-tasks.register<Test>("IntegrationTestServiceAccountCreds") {
-  dependsOn(tasks.shadowJar)
-  dependsOn(tasks.named("copyAgent"))
-
-  useJUnitPlatform()
-  // include only the integration test file
-  include("io/opentelemetry/contrib/gcp/auth/GcpAuthExtensionEndToEndTest.class")
-
-  val fakeCredsFilePath = project.file("src/test/resources/fake_service_account_creds.json").absolutePath
-
-  environment("GOOGLE_CLOUD_QUOTA_PROJECT", "quota-project-id")
-  environment("GOOGLE_APPLICATION_CREDENTIALS", fakeCredsFilePath)
-  jvmArgs = listOf(
-    "-javaagent:$javaAgentJarPath",
-    "-Dotel.javaagent.extensions=$authExtensionJarPath",
-    "-Dgoogle.cloud.project=my-gcp-project",
-    "-Dotel.java.global-autoconfigure.enabled=true",
-    "-Dotel.exporter.otlp.endpoint=http://localhost:4318",
-    "-Dotel.resource.providers.gcp.enabled=true",
-    "-Dotel.traces.exporter=otlp",
-    "-Dotel.bsp.schedule.delay=2000",
-    "-Dotel.metrics.exporter=none",
-    "-Dotel.logs.exporter=none",
-    "-Dotel.exporter.otlp.protocol=http/protobuf",
-    "-Dmockserver.logLevel=off"
+    "-Dotel.javaagent.debug=false",
+    "-Dmockserver.logLevel=trace"
   )
 }

gcp-auth-extension/src/test/java/io/opentelemetry/contrib/gcp/auth/GcpAuthExtensionEndToEndTest.java

@@ -89,10 +89,9 @@ public static void setup() throws NoSuchAlgorithmException, KeyManagementExcepti
     // Set up mock OTLP backend server to which traces will be exported
     backendServer = ClientAndServer.startClientAndServer(EXPORTER_ENDPOINT_PORT);
     backendServer.when(request()).respond(response().withStatusCode(200));
-
-    // Set up the mock gcp metadata server to provide fake credentials
     String accessTokenResponse =
         "{\"access_token\": \"fake.access_token\",\"expires_in\": 3600, \"token_type\": \"Bearer\"}";
+
     mockGcpOAuth2Server = ClientAndServer.startClientAndServer(MOCK_GCP_OAUTH2_PORT);
 
     MockServerClient mockServerClient =