Finally got it accepted by the BB Portal.
Step 1: Download
Android Studio Plug-in
https://developer.blackberry.com/android/tools/
Step 2: Download your .csk and .csj file and choose password. Use same password for both files. You will see 3 options. "TOP" 10.2 or above is the .csj file that will be sent to your email. "MIDDLE" is the .csk file that will be created instantly. "BOTTOM" is older version which i did not fill.
https://developer.blackberry.com/codesigning
Run
BlackBerry APK Packager.exe from the Android Studio Plug-in
I ran this for the first time, selected my APK and was not successful with converting and signing the APK. It directed me to configure the Developer Certificates and Blackberry ID Token (Which is one of those .exe file). There are 3 options to fill. BlackBerry ID Token is the .csk file you downloaded. For Developer Certificates you just fill it out. The legacy, I just left it alone.
Before I discovered this, I was going through lots of trials and errors using the command line and BlackBerry Graphical Aid. I ask myself how is .csj used in Android Studio Plug in? Not sure how, but with BlackBerry Graphical Aid or Command Line I was successfully able to Register the .cjs file. Is this required? Sorry, I don't know much about it.
Good Luck!
P.S. You will need to register with BlackBerry App Portal for an account. Which is free
