The feature is available on all platforms including Android. Now you can type a "/" symbol on your Discord channel to see all available bot commands in the list. On the same menu, you also will be able to switch between different sections of commands like "built-in" and others that are bot specific.
After selecting a specific command, you will see an additional prompt where you can pass your parameters and click on the send button.
How to test:
- Open a Discord server (for ex. XDA) where you have access to bot commands.
- Select a chat where bot commands are enabled.
- Type the "/" symbol to see the list of available commands.
Source: Discord blog