modifying Embed-Dependency (mentioned here) it is working with current mysql-connector-java (8.0.19) tested on ursim 5.6
pom:
<Import-Package>
com.ur.urcap.api*; mysql*;resolution:=optional,com.google.protobuf.*;resolution:=optional,com.mchange.*;resolution:=optional,org.jboss.resource.*;resolution:=optional,org.slf4j*;resolution:=optional, *
</Import-Package>
<Embed-Dependency>
!mysql, !org.osgi.core, !com.ur.urcap.api, *; scope=compile|runtime
</Embed-Dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.19</version>
</dependency>
edit:
and tested on a real robot