Related to JENKINS-37386 - now that we're getting @Symbol on ToolDescriptor, it makes sense to change the tool step to take either the descriptor ID (i.e., the class name) or the relevant symbol.
Add a convenience static method for getting @Symbol values off an object
Add @Symbol to ToolDescriptors
PR up at https://github.com/jenkinsci/workflow-basic-steps-plugin/pull/16
Code changed in jenkins
User: Andrew Bayer
[FIXED JENKINS-37397] Allow use of @Symbols from tools as tool types.
Fall back to allowing descriptor IDs as well.