rxValidationKotlin2.kt

val textInputLayouts = arrayOf(
                tilFirstName,
                tilLastName,
                tilEmail,
                tilPhone,
                tilYear,
                tilDob,
                tilPassword,
                tilConfirmPassword)

        RxValidationTextInputLayout.combineOnReady(*textInputLayouts) { observable ->
            disposable = observable.subscribe { btnSignIn.isEnabled = it }
        }