java_gen: value types: add NO_MASK, FULL_MASK constants where missing

This is necessary so types can distinguish non-canonical forms.
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFBooleanValue.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFBooleanValue.java
index b386e54..e276092 100644
--- a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFBooleanValue.java
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFBooleanValue.java
@@ -28,6 +28,9 @@
     public final static OFBooleanValue TRUE = new OFBooleanValue(true);
     public final static OFBooleanValue FALSE = new OFBooleanValue(false);
 
+    public final static OFBooleanValue NO_MASK = TRUE;
+    public final static OFBooleanValue FULL_MASK = FALSE;
+
     private final boolean value;
 
     private OFBooleanValue(boolean value) {