FROM AOSC: Use system AA font by default

Backport of 38a1699

Author: xtexx

jdk/src/share/classes/sun/awt/SunToolkit.java

@@ -1831,6 +1831,9 @@ private static boolean useSystemAAFontSettings() {
                     AccessController.doPrivileged(
                          new GetPropertyAction("awt.useSystemAAFontSettings"));
             }
+            if (systemAAFonts == null) {
+                systemAAFonts = "on";
+            }
             if (systemAAFonts != null) {
                 useSystemAAFontSettings =
                     Boolean.valueOf(systemAAFonts).booleanValue();