Back Gesture Should Close Emote Picker, Not Entire Chat

When the emote picker is open within a chat window, performing the system back gesture (or tapping the back button) currently closes the entire chat screen. It would be more intuitive and user-friendly if the back gesture first closed the emote picker overlay, returning the user to the active chat input field, rather than exiting the chat completely. Subsequent back gestures could then navigate away from the chat.