* Bump NDK to 23.1.7779620

* Do not symlink clang

* Symlink clang 12.0.8 to 9.0.8 for BUCK

* symlink llvm to arm-linux-androideabi-4.9

* Remove /

* symlink sysroot

* Diverge the NDK version between Buck & Gradle

* Add a `CMAKE_BIN_PATH` variable to the PATH

* Configure `KOTLIN_HOME`

Removes API 30 tools used for compatibility with the main repo.

NDK 21

Co-authored-by: Subramanya Chakravarthy <subramanyachakravarthy@Subramanyas-MacBook-Pro.local>

Co-authored-by: Pierre-Alexandre Dupuy <pierre-alexandre.dupuy@ecov.fr>

Changes:
* Bump Android SDK to 30

install gcc, g++, make instead of build-essential

Breaking changes
- remove cmake from apt
- remove python version 2
- remove ruby
- openjdk 8 headless

This reverts commit 1b7e96b2.

* remove m2repository
* remove add-ons