Add an App Icon for ODK Skunkworks-Crow Android Application

1. What is the general goal of the feature?

As we know, by GSoC 2018 and GSoC 2019, we have Skunkworks-Crow, a new android application for form data exchanging. But this android application doesn't have an icon for now. We already have an issue and PR in our Github repo, so please refer to them and give your suggestions!


Thank you so much about that.

2. What are some example use cases for this feature?
Here are some proposals for reference.

3. What can you contribute to making this feature a reality?
I have a PR, and if you have any ideas, feel free to discuss at #117. We are looking forward to that! Thank you.