f0508d342f
We made the assumption that the user needs to navigate to the setting to enable or disable the talkback, but there is a way to add a talkback switch on the bottom navigation bar. So the talkback can be enabled/disabled when the application is resumed. Since the UI may render differently depending on the talkback state, we need to make the composable `isTalkbackActive()` backed on a mutable state.