missing overrides in immutableHashMap

Signed-off-by: MeeniMc <68366846+MeeniMc@users.noreply.github.com>

src/main/java/com/google/common/collect/HydrogenImmutableReferenceHashMap.java

@@ -116,6 +116,16 @@ ImmutableSet<Entry<K, V>> createEntrySet() {
         return new HydrogenEntrySet<>(this.key, this.value, this.size);
     }
 
+    @Override
+    ImmutableSet<K> createKeySet() {
+        return new ImmutableMapKeySet<>(this);
+    }
+
+    @Override
+    ImmutableCollection<V> createValues() {
+        return new ImmutableMapValues<>(this);
+    }
+
     @Override
     boolean isPartialView() {
         return false;