Remove duplicate virutal field (#15475)

Author: laurit

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/Servlet3FilterInitAdvice.java

@@ -5,7 +5,7 @@
 
 package io.opentelemetry.javaagent.instrumentation.servlet.v3_0;
 
-import static io.opentelemetry.javaagent.instrumentation.servlet.v3_0.Servlet3Singletons.FILTER_MAPPING_RESOLVER_FACTORY;
+import static io.opentelemetry.javaagent.instrumentation.servlet.v3_0.Servlet3Singletons.FILTER_MAPPING_RESOLVER;
 
 import javax.servlet.Filter;
 import javax.servlet.FilterConfig;
@@ -20,7 +20,6 @@ public static void filterInit(
     if (filterConfig == null) {
       return;
     }
-    FILTER_MAPPING_RESOLVER_FACTORY.set(
-        filter, new Servlet3FilterMappingResolverFactory(filterConfig));
+    FILTER_MAPPING_RESOLVER.set(filter, new Servlet3FilterMappingResolverFactory(filterConfig));
   }
 }

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/Servlet3InitAdvice.java

@@ -5,7 +5,7 @@
 
 package io.opentelemetry.javaagent.instrumentation.servlet.v3_0;
 
-import static io.opentelemetry.javaagent.instrumentation.servlet.v3_0.Servlet3Singletons.SERVLET_MAPPING_RESOLVER_FACTORY;
+import static io.opentelemetry.javaagent.instrumentation.servlet.v3_0.Servlet3Singletons.SERVLET_MAPPING_RESOLVER;
 
 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
@@ -20,7 +20,6 @@ public static void servletInit(
     if (servletConfig == null) {
       return;
     }
-    SERVLET_MAPPING_RESOLVER_FACTORY.set(
-        servlet, new Servlet3MappingResolverFactory(servletConfig));
+    SERVLET_MAPPING_RESOLVER.set(servlet, new Servlet3MappingResolverFactory(servletConfig));
   }
 }

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/Servlet3Singletons.java

@@ -24,14 +24,6 @@
 public final class Servlet3Singletons {
   private static final String INSTRUMENTATION_NAME = "io.opentelemetry.servlet-3.0";
 
-  public static final VirtualField<Servlet, MappingResolver.Factory>
-      SERVLET_MAPPING_RESOLVER_FACTORY =
-          VirtualField.find(Servlet.class, MappingResolver.Factory.class);
-
-  public static final VirtualField<Filter, MappingResolver.Factory>
-      FILTER_MAPPING_RESOLVER_FACTORY =
-          VirtualField.find(Filter.class, MappingResolver.Factory.class);
-
   private static final Instrumenter<
           ServletRequestContext<HttpServletRequest>, ServletResponseContext<HttpServletResponse>>
       INSTRUMENTER =
@@ -41,9 +33,9 @@ public final class Servlet3Singletons {
   private static final ServletHelper<HttpServletRequest, HttpServletResponse> HELPER =
       new ServletHelper<>(INSTRUMENTER, Servlet3Accessor.INSTANCE);
 
-  private static final VirtualField<Servlet, MappingResolver.Factory> SERVLET_MAPPING_RESOLVER =
+  public static final VirtualField<Servlet, MappingResolver.Factory> SERVLET_MAPPING_RESOLVER =
       VirtualField.find(Servlet.class, MappingResolver.Factory.class);
-  private static final VirtualField<Filter, MappingResolver.Factory> FILTER_MAPPING_RESOLVER =
+  public static final VirtualField<Filter, MappingResolver.Factory> FILTER_MAPPING_RESOLVER =
       VirtualField.find(Filter.class, MappingResolver.Factory.class);
 
   private static final Instrumenter<ClassAndMethod, Void> RESPONSE_INSTRUMENTER =