Hide frequently used emoji tab when empty

[IlarionHalushka]

Preconditions: Reinstall app so there are no frequently used emoji yet.

Steps to reproduce:

1. Open Room View screen
2. Click on Emoji button on the left

Expected: Frequently used tab is not displayed because it's empty.
Actual: Frequently used tab is displayed with empty content.

Screenshot: https://prnt.sc/n8mro3

Your Rocket.Chat Experimental app version: branch develop 1.11.0.100
Your Rocket.Chat server version: open.rocket.chat
Device (or Simulator) you're running with: simulator iOS iPhone X, emulator Android Nexus 5 API 27