Now it is possible don’t worry, here is the full and final steps to reset .JKS file.
UPDATE: As it states in the Play Console Help here (scroll to bottom), you should now already do step 3 before (create new .jks, convert to .pem) and only then fill out the form with the upload_cert and .pem file attached. This will make the support process easier and faster for you.
Step-1
Download the UPLOAD CERTIFICATE (file name – upload_cert.der) from your Google Play Store Console
Step-2
Go to this LINK https://support.google.com/googleplay/android-developer/contact/key?hl=en And fill the application form with your valid Email ID and upload the file (upload_cert.der).
Step-3
Now you will get the Email from support team, and they don’t need your .JKS file but .PEM file here is the email Sample.
Step-4
to convert .JKS file to .PEM file you just have to download KeyStore Explorer
After replying the Mail, wait for 48 to 72 hours your keystore fill will reset.