According to the Apples documentation, this should work well on iOS devices. However, I connected an iPhone along with Apple Bluetooth keyboard and tried the above code. It didn't work, no matter what tried. It also didn't work on Asus Transformer, running Android 4.1.1.
Further, I would suggest you to contact Apple and/or Google and see if there isn't something specific that we are missing about this attribute.
I hope this answer helps.
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