DevOps: fix CircleCI builds for mobile apps

[evereq]

We recently switched to Machine builds in Circle from Docker-based builds (so we got more RAM). However, we did not switch yet builds for Android apps correctly. They used Docker image circleci/android:api-29-node, so now we need to install all that Android SDK, Cordova, Build Tools and tons of other things manually on the machine inside CircleCI build.

See as example dockerfile: https://github.com/CircleCI-Public/circleci-dockerfiles/blob/master/android/images/api-29-node/Dockerfile

Note: of course in our case, it will be different because we use the Ubuntu machine, etc.

[evereq]

Fixed using few tricks:

• added dependencies to package.json in the root (weird, but that helps Cordova builds)
• added Android SDK setup for Ubuntu machine (with tons of issues like licenses acceptance etc)