Review fixes for java-http-server:javaagent (#17383)

Co-authored-by: otelbot <197425009+otelbot@users.noreply.github.com>
Co-authored-by: Trask Stalnaker <trask.stalnaker@gmail.com>

Author: otelbot[bot]

instrumentation/java-http-server/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/javahttpserver/HttpServerInstrumentation.java

@@ -34,7 +34,7 @@ public static class BuildAdvice {
 
     @Advice.OnMethodExit(suppress = Throwable.class)
     public static void onExit(@Advice.Return HttpContext httpContext) {
-      httpContext.getFilters().addAll(JavaHttpServerSingletons.FILTERS);
+      httpContext.getFilters().addAll(JavaHttpServerSingletons.filters);
     }
   }
 }

instrumentation/java-http-server/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/javahttpserver/JavaHttpServerSingletons.java

@@ -18,7 +18,7 @@
 
 public final class JavaHttpServerSingletons {
 
-  public static final List<Filter> FILTERS;
+  public static final List<Filter> filters;
 
   static {
     CommonConfig config = AgentCommonConfig.get();
@@ -30,7 +30,7 @@ public final class JavaHttpServerSingletons {
         .configure(config);
     JavaHttpServerTelemetry serverTelemetry = serverBuilder.build();
 
-    FILTERS = asList(serverTelemetry.createFilter(), new ResponseCustomizingFilter());
+    filters = asList(serverTelemetry.createFilter(), new ResponseCustomizingFilter());
   }
 
   private JavaHttpServerSingletons() {}