Compensation for mouse acceleration in android

- [X] I have checked that a similar [feature request](https://github.com/Genymobile/scrcpy/issues?q=is%3Aopen+is%3Aissue+label%3A%22feature+request%22) does not already exist.

**Is your feature request related to a problem? Please describe.**
When trying to game using ``--otg`` I realized the presence of that annoying mouse acceleration. This tool could be really useful for gaming (or maybe even normal use can be improved) only if it had this feature and key mapping (but maybe there are tools for that already?).

**Describe the solution you'd like**
A flag where we can pass a value which will determine how much deceleration (or whatever is the opposite of mouse acceleration) to apply before passing the mouse input. Better yet hardcode a value which will always work (if that is possible).

**Describe alternatives you've considered**
I tried searching the web and in my phone but I couldn't find a way to disable mouse acceleration without rooting.

**Additional context**
Not needed?