Go to Settings > Security > Install from storage.

install programatically can be achived by from command line, by moving certs to

replacing bks file solely is useless, it has to be combined with the password

https://github.com/danzeeeman/meerkat-decompiled/blob/master/io/fabric/sdk/android/services/network/PinningInfoProvider.java

set proxy programatically

1. set mannully for one
2. pull /data/misc/wifi/ipconfig.txt
3. push to other devices

如何安装证书

make certs like this tutorial, http://forum.xda-developers.com/google-nexus-5/help/howto-install-custom-cert-network-t2533550
but push it to /data/misc/user/0/cacerts-added/