I was getting the same error, I try this command
keytool -genkey -v -keystore ~/upload-keystore.jks -keyalg RSA -keysize 2048 -validity 10000 -alias upload -storetype JKS
with extra attribute
-storetype JKS
it helps me to solve my problem and successfully create bundle.
The -storetype JKS tag is only required for Java 9 or newer. As of the Java 9 release, the keystore type defaults to PKS12.