Fix missing static imports for BODY_MULTIPART_REPEATED and BODY_MULTIPART_COMBINED

Author: jandro996

dd-java-agent/instrumentation-testing/src/main/groovy/datadog/trace/agent/test/base/HttpServerTest.groovy

@@ -65,6 +65,8 @@ import java.util.function.Supplier
 
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_JSON
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_COMBINED
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_REPEATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_URLENCODED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED_IS