环境：macOS、Intellij IDEA 2019.1
问题
No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android
This version of the NDK may be incompatible with the Android Gradle plugin version 3.0 or older.
Please use plugin version 3.1 or newer.
Upgrade plugin to version 3.1.0 and sync project
解决办法
下载NDK(建议Android NDK，修订版 16b)，然后把 toolchains 里的 mips 拷贝到NDK对应目录下
https://developer.android.google.cn/ndk/downloads/older_releases.html
