Free Service for Alpha Zero training
You might be able to fit your training into a Google Colab session. You can search for tutorials using different libraries, here is one for PyTorch. Google Colab is essentially a free online Jupyter notebook, and makes K80 GPU available for acceleration. 

Sessions on Colab are limited to ~12 hours maximum, so you would need to start with some simple variants and build up to max allowed training time (this is good practice anyway). There is no guarantee that this will be enough for your game, but you should learn a lot even if the resulting agent is not perfect.

It is not clear whether you have already figured this out, but you most likely will not be able to host the Android App natively to run as the environment, and will need to code some kind of simulation or re-implement the game. I would also assume it is a card, board or turn-based strategy game with perfect information, if you are hoping to use an AlphaZero-based learning agent with it (AlphaZero could probably be adapted to video games, but I would not expect it be as efficient as simpler algorithms without a planning phase, such as A3C in that case).