Thanks for the ping Grum!
Currently, there is no way to install plugins on Android, I’m afraid. Python does support Android, it is just something that nobody has tried to get working for Krita, yet.
Do you happen to use the Nightly build of Krita? This four-finger tap gesture is only present in it. You can enter and exit canvas-only mode with it. Mobile experience is pretty bad presently. There are some things which were implemented recently for ChromeOS like moving/resizing dialogs, mmaaaaybe that could help a bit.