Add chrome.bluetooth and chrome.bluetoothLowEnergy for android

Yes, I will do that. The "properties" are not this property strings. They are `value` field of `GattCharacteristic` and `GattDescriptor`. For example, `buildCharacteristicInfo` does not send `value` because we need to send an array of `characteristicInfo`, but  `buildCharacteristicMultipartInfo` does send `value` field. I will add some comments on these `build*` methods.