I have no idea about how to install a CA certificate programmatically. I only know to do it from Settings->Security and PRivacy-> Other Security settings -> Install from device storage -> Ca certificate.
I select the certificate from device storage and it installs it.
However the requirement is to install them as a part of the application i.e programmatically replicate the above installation through an app. User interaction for permission is okay. Please let me know the steps to follow.