Fix that getClasses() method returns protected classes

In publicOnly condition, Dalvik_java_lang_Class_getDeclaredClasses()
returns non-public(protected) declared class.
It is not match with documentation and the result of host java vm.
Protected inner declared class is generated as ‘public’ class via host javac.
But, has ‘protected’ constructor.
This fix add check constructor’s modifier to decide whether public or not.
Related issue: http://code.google.com/p/android/issues/detail?id=60394

Change-Id: Ib93f8f8b117129a9fc588f5884490308c26cb802