8235670: Javadoc pages not printing correctly in some browsers

Reviewed-by: jjg, prappo

src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/resources/stylesheet.css

@@ -124,6 +124,7 @@ button {
 /*
  * Styles for navigation bar.
  */
+@media screen {
     .flexBox {
         position:fixed;
         display:flex;
@@ -138,6 +139,7 @@ button {
         flex: 1 1 auto;
         overflow-y: auto;
     }
+}
 .topNav {
     background-color:#4D7A97;
     color:#FFFFFF;
@@ -226,6 +228,14 @@ ul.subNavList li {
     left:-9999px;
     overflow:hidden;
 }
+/*
+ * Hide navigation links and search box in print layout
+ */
+@media print {
+    ul.navList, div.subNav  {
+        display:none;
+    }
+}
 /*
  * Styles for page header and footer.
  */