recipe for target 'ninja_wrapper' failed

編譯Android 7.0以上的源碼時須要用到Jack Server，編譯過程有可能出現一下錯誤：

1 error generated. [ 43% 29709/68905] build camscope-autogen ninja: build stopped: subcommand failed. build/core/ninja.mk:148: recipe for target 'ninja_wrapper' failed make: *** [ninja_wrapper] Error 1

這個錯誤若是是因爲Java VM內存不足致使的（上面會有out fo memory提示），解決：

1. export JACK_SERVER_VM_ARGUMENTS="-Dfile.encoding=UTF-8 -XX:+TieredCompilation -Xmx4096m"  
2. prebuilts/sdk/tools/jack-admin kill-server  
3. prebuilts/sdk/tools/jack-admin start-server

不過建議編譯機器的內存大於8G。