Set KeyMayExist fields visibility to public (#9285)

Summary:
Fixes https://github.com/facebook/rocksdb/issues/9284

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9285

Reviewed By: pdillinger

Differential Revision: D33062006

Pulled By: mrambacher

fbshipit-source-id: c3471c2db717fa5bc2337cf996ce744af0ed877d

java/src/main/java/org/rocksdb/KeyMayExist.java

@@ -23,7 +23,7 @@ public class KeyMayExist {
     return Objects.hash(exists, valueLength);
   }
 
-  enum KeyMayExistEnum { kNotExist, kExistsWithoutValue, kExistsWithValue }
+  public enum KeyMayExistEnum { kNotExist, kExistsWithoutValue, kExistsWithValue }
   ;
 
   public KeyMayExist(final KeyMayExistEnum exists, final int valueLength) {
@@ -31,6 +31,6 @@ public class KeyMayExist {
     this.valueLength = valueLength;
   }
 
-  final KeyMayExistEnum exists;
+  public final KeyMayExistEnum exists;
-  final int valueLength;
+  public final int valueLength;
 }