ref.: http://stackoverflow.com/questions/3406534/password-hint-font-in-android/18073897#18073897
Solution
android:fontFamily="sans-serif"From Dialogs Guide
Tip: By default, when you set an EditText element to use the “textPassword” input type, the font family is set to monospace, so you should change its font family to “sans-serif” so that both text fields use a matching font style.