I'm not sure if there is anything like AutoHotKey in Android but it is possible to get the timestamp in that format for the current time on demand.
You'd need Tasker or any other app which can run a command.
Setup a task with these actions:
- Code → Run Shell:
- Command:
date "+%Y%m%d%H%M%S"
- Store Output In:
%date
- System → Set Clipboard → Text:
%date
- Now, exit the Tasker, go back to Home Screen, long press your home screen to add a widget and choose Task Shortcut → pick your newly created Task → assign an icon at the bottom. That's it.
Whenever you would press that icon on your home screen, the current date-time would be copied in your clipboard automatically in the supplied format. You just have to copy paste it wherever you want it. There can be other methods to run a Tasker task less disruptively, such as through quick settings, as mentioned here by Grayox96 on Reddit.