Clean-up all projects to remove fennec bits we don't need for fenix

We should clean-up the firefox project and others to remove the mobile bits (this includes removing the mozconfig files, among others) we don't need for fenix. geckoview is the new black for mobile.

This includes getting rid of the android-armv7 vs. android-fenix-armv7 distinction.

Edited Aug 31, 2020 by Georg Koppen

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information