The apache commons-lang:commons-lang is available, this add org.apache.commons:commons-lang3 so those wishing can slim their dependencies as it's provided within the code.
Internal usage is also upgrade to commons-lang3.
Separate issue could be, drop commons-lang from jenkins v3.
Creating 2 api-plugins as a different longer term solution. Those being;
1) commons-lang-api-plugin
2) commons-lang3-api-plugin