send null instead of empty string for action sheet message
send null instead of empty string for action sheet message

If the user wants to display only action sheet buttons w/o any text and
he sends null as message, the empty string causes an empty title to be
shown above the buttons. Having null instead, completely eliminates the
empty space.

hdeshev/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript,hdeshev/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript,NativeScript/NativeScript,hdeshev/NativeScript