Fastboot and adb for Android devices

Build with NDK, for libcrypto please read " Building Prerequisites " section in https://boringssl.googlesource.com/boringssl/+/HEAD/BUILDING.md

Steps:

1. sh 01_getsource.sh to get source codes
2. sh 02_build_libcrypto.sh to build libcrypto.a (will be at src/boringssl/dist)
3. sh 03_build_fastboot.sh to build fastboot binary
4. sh 04_build_adb.sh to build adb binary

Only tested on Android 6.0 device.