Android support for MOTION

[robinhundt]

MOTION should get support for Android, specifically the arm64-v8a ABI with neon support. In order to achieve this, there are some prerequisites:

• Use SIMD abstraction library for instrinsics Adopt SIMD abstraction library for Android support #10
• Remove or cross compile OpenSSL Remove OpenSSL dependency #8
• Cross compile boost
  • https://github.com/moritz-wundke/Boost-for-Android should probably be used
• Cross compile fmt
• Cross compile flatbuffers
• Cross compile googletest
  • tests would probably need to be adapted to work on Android
  • the ndk ships an android compatible googletest implementation
  • Note: While it would be very nice to execute the tests on android, this isn't strictly necessary for Android support of MOTION