I also modified my cacerts file to include a corpo firewall CA cert, but instead of having to reinstall Android Studio, I just
Download the full .zip from Google's Archive that corresponded to my current version (in my case 3.1.3), then
Extract the cacerts file and replaced my modified one.
Run the update patch normally.
You will probably need to re-add your company CA to the newer version of cacerts. And if you are like me and don't deal with keytool very often, you probably don't remember the command so here you go (Password is changeit, but don't :)
keytool -import -alias key_alias -file "C:\Path\to\corpo_cert.der" -keystore "C:\Program Files\Android\Android Studio\jre\jre\lib\security\cacerts"