Extend testBodyFilenamesCalledOnce coverage to Jetty 9.x and 10.x

- Add BODY_MULTIPART_REPEATED case to TestServlet3 (javax) so Jetty 9.x/10.x
  test modules can exercise the repeated getParts() scenario
- Enable testBodyFilenamesCalledOnce() for Jetty 9.0, 9.0.4, 9.3, 9.4.21, and 10.0

Author: jandro996

dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-10.0/src/test/groovy/datadog/trace/instrumentation/jetty10/Jetty10Test.groovy

@@ -90,6 +90,11 @@ abstract class Jetty10Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true

dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0.4/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy

@@ -90,6 +90,11 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true

dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.0/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy

@@ -89,6 +89,11 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true

dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.3/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy

@@ -89,6 +89,11 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true

dd-java-agent/instrumentation/jetty/jetty-server/jetty-server-9.4.21/src/test/groovy/datadog/trace/instrumentation/jetty9/Jetty9Test.groovy

@@ -90,6 +90,11 @@ abstract class Jetty9Test extends HttpServerTest<Server> {
     true
   }
 
+  @Override
+  boolean testBodyFilenamesCalledOnce() {
+    true
+  }
+
   @Override
   boolean testSessionId() {
     true

dd-java-agent/instrumentation/servlet/javax-servlet/javax-servlet-3.0/src/testFixtures/groovy/datadog/trace/instrumentation/servlet3/TestServlet3.groovy

@@ -15,6 +15,7 @@ import java.lang.reflect.Modifier
 
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_URLENCODED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART
+import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.BODY_MULTIPART_REPEATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CREATED_IS
 import static datadog.trace.agent.test.base.HttpServerTest.ServerEndpoint.CUSTOM_EXCEPTION
@@ -95,6 +96,14 @@ class TestServlet3 {
             resp.status = endpoint.status
             resp.writer.print(endpoint.bodyForQuery(req.queryString))
             break
+          case BODY_MULTIPART_REPEATED:
+            resp.status = endpoint.status
+          // Call getParts() 3 times to verify the filenames callback fires only once
+            req.getParts()
+            req.getParts()
+            req.getParts()
+            resp.writer.print(endpoint.body)
+            break
           case BODY_URLENCODED:
           case BODY_MULTIPART:
             resp.status = endpoint.status