[JENKINS-48593] - Add getSystemProperty(key) to fix hudson.consoleTailKB system property (#3200)
[JENKINS-48593] - Add getSystemProperty(key) to fix hudson.consoleTailKB system property (#3200)

* Add getSystemProperty(key) to fix hudson.consoleTailKB system property

* Add Javadoc, @Restricted and delegate to SystemProperties

These changes were requested by @daniel-beck.

* PR was not merged in time for 2.96

* Changes as requested by @oleg-nenashev

(cherry picked from commit 006c51256e58d9b691956962d9fd624fb0c1e08b)

andresrc/jenkins,kohsuke/hudson,DanielWeber/jenkins,amuniz/jenkins,dariver/jenkins,pjanouse/jenkins,aldaris/jenkins,stephenc/jenkins,andresrc/jenkins,patbos/jenkins,jenkinsci/jenkins,jenkinsci/jenkins,pjanouse/jenkins,sathiya-mit/jenkins,recena/jenkins,Vlatombe/jenkins,kohsuke/hudson,v1v/jenkins,godfath3r/jenkins,damianszczepanik/jenkins,Jochen-A-Fuerbacher/jenkins,Jochen-A-Fuerbacher/jenkins,dariver/jenkins,patbos/jenkins,bkmeneguello/jenkins,viqueen/jenkins,ikedam/jenkins,Jochen-A-Fuerbacher/jenkins,aldaris/jenkins,Jochen-A-Fuerbacher/jenkins,oleg-nenashev/jenkins,amuniz/jenkins,godfath3r/jenkins,ikedam/jenkins,Vlatombe/jenkins,recena/jenkins,ikedam/jenkins,ikedam/jenkins,Jochen-A-Fuerbacher/jenkins,andresrc/jenkins,batmat/jenkins,pjanouse/jenkins,DanielWeber/jenkins,aldaris/jenkins,godfath3r/jenkins,sathiya-mit/jenkins,kohsuke/hudson,daniel-beck/jenkins,v1v/jenkins,viqueen/jenkins,ErikVerheul/jenkins,bkmeneguello/jenkins,jenkinsci/jenkins,godfath3r/jenkins,v1v/jenkins,ikedam/jenkins,viqueen/jenkins,kohsuke/hudson,patbos/jenkins,rsandell/jenkins,andresrc/jenkins,patbos/jenkins,v1v/jenkins,dariver/jenkins,Vlatombe/jenkins,sathiya-mit/jenkins,damianszczepanik/jenkins,amuniz/jenkins,patbos/jenkins,oleg-nenashev/jenkins,sathiya-mit/jenkins,Vlatombe/jenkins,batmat/jenkins,stephenc/jenkins,sathiya-mit/jenkins,batmat/jenkins,Jochen-A-Fuerbacher/jenkins,ErikVerheul/jenkins,daniel-beck/jenkins,dariver/jenkins,andresrc/jenkins,aldaris/jenkins,damianszczepanik/jenkins,jenkinsci/jenkins,damianszczepanik/jenkins,v1v/jenkins,aldaris/jenkins,ErikVerheul/jenkins,recena/jenkins,recena/jenkins,Vlatombe/jenkins,patbos/jenkins,ErikVerheul/jenkins,damianszczepanik/jenkins,DanielWeber/jenkins,Vlatombe/jenkins,damianszczepanik/jenkins,rsandell/jenkins,pjanouse/jenkins,DanielWeber/jenkins,ikedam/jenkins,daniel-beck/jenkins,daniel-beck/jenkins,MarkEWaite/jenkins,oleg-nenashev/jenkins,andresrc/jenkins,DanielWeber/jenkins,recena/jenkins,jenkinsci/jenkins,dariver/jenkins,bkmeneguello/jenkins,viqueen/jenkins,andresrc/jenkins,bkmeneguello/jenkins,stephenc/jenkins,recena/jenkins,viqueen/jenkins,MarkEWaite/jenkins,godfath3r/jenkins,ikedam/jenkins,batmat/jenkins,sathiya-mit/jenkins,bkmeneguello/jenkins,oleg-nenashev/jenkins,oleg-nenashev/jenkins,MarkEWaite/jenkins,aldaris/jenkins,jenkinsci/jenkins,batmat/jenkins,patbos/jenkins,MarkEWaite/jenkins,MarkEWaite/jenkins,Jochen-A-Fuerbacher/jenkins,batmat/jenkins,oleg-nenashev/jenkins,Vlatombe/jenkins,sathiya-mit/jenkins,rsandell/jenkins,kohsuke/hudson,stephenc/jenkins,DanielWeber/jenkins,daniel-beck/jenkins,DanielWeber/jenkins,daniel-beck/jenkins,rsandell/jenkins,MarkEWaite/jenkins,amuniz/jenkins,rsandell/jenkins,rsandell/jenkins,pjanouse/jenkins,bkmeneguello/jenkins,godfath3r/jenkins,pjanouse/jenkins,pjanouse/jenkins,jenkinsci/jenkins,batmat/jenkins,kohsuke/hudson,amuniz/jenkins,kohsuke/hudson,v1v/jenkins,amuniz/jenkins,MarkEWaite/jenkins,MarkEWaite/jenkins,ikedam/jenkins,bkmeneguello/jenkins,damianszczepanik/jenkins,aldaris/jenkins,daniel-beck/jenkins,kohsuke/hudson,viqueen/jenkins,stephenc/jenkins,v1v/jenkins,stephenc/jenkins,ErikVerheul/jenkins,damianszczepanik/jenkins,recena/jenkins,viqueen/jenkins,oleg-nenashev/jenkins,rsandell/jenkins,dariver/jenkins,amuniz/jenkins,ErikVerheul/jenkins,dariver/jenkins,godfath3r/jenkins,stephenc/jenkins,ErikVerheul/jenkins,jenkinsci/jenkins,daniel-beck/jenkins,rsandell/jenkins