Added validation for 'uuid' field being present.
Added validation for 'uuid' field being present.

This change adds validation to ensure `uuid` field is always present
in `Call::Update::TaskStatus` message sent by the Executor.

Review: https://reviews.apache.org/r/40562

jpeach/mesos,craimbert/mesos,Gilbert88/mesos,dforsyth/mesos,reneploetz/mesos,zmalik/mesos,Gilbert88/mesos,reneploetz/mesos,dforsyth/mesos,abudnik/mesos,reneploetz/mesos,Aman-Jain-14/customizedMesos,Gilbert88/mesos,Gilbert88/mesos,reneploetz/mesos,zmalik/mesos,andschwa/mesos,kaysoky/mesos,asamerh4/mesos,jpeach/mesos,craimbert/mesos,yuquanshan/customizedMesos,asamerh4/mesos,jpeach/mesos,abudnik/mesos,yuquanshan/customizedMesos,asamerh4/mesos,dforsyth/mesos,jpeach/mesos,Gilbert88/mesos,jpeach/mesos,chhsia0/mesos,neilconway/mesos,neilconway/mesos,gsantovena/mesos,reneploetz/mesos,yuquanshan/customizedMesos,andschwa/mesos,craimbert/mesos,dforsyth/mesos,kaysoky/mesos,kaysoky/mesos,Aman-Jain-14/customizedMesos,reneploetz/mesos,neilconway/mesos,chhsia0/mesos,dforsyth/mesos,neilconway/mesos,kaysoky/mesos,asamerh4/mesos,Aman-Jain-14/customizedMesos,abudnik/mesos,yuquanshan/customizedMesos,verizonlabs/mesos,gsantovena/mesos,dforsyth/mesos,andschwa/mesos,Aman-Jain-14/customizedMesos,chhsia0/mesos,jpeach/mesos,chhsia0/mesos,abudnik/mesos,Aman-Jain-14/customizedMesos,yuquanshan/customizedMesos,gsantovena/mesos,verizonlabs/mesos,asamerh4/mesos,chhsia0/mesos,neilconway/mesos,abudnik/mesos,abudnik/mesos,craimbert/mesos,dforsyth/mesos,craimbert/mesos,zmalik/mesos,craimbert/mesos,chhsia0/mesos,zmalik/mesos,andschwa/mesos,verizonlabs/mesos,craimbert/mesos,zmalik/mesos,chhsia0/mesos,Gilbert88/mesos,verizonlabs/mesos,asamerh4/mesos,gsantovena/mesos,andschwa/mesos,gsantovena/mesos,neilconway/mesos,kaysoky/mesos,Gilbert88/mesos,gsantovena/mesos,kaysoky/mesos,kaysoky/mesos,reneploetz/mesos,verizonlabs/mesos,jpeach/mesos,verizonlabs/mesos,yuquanshan/customizedMesos,andschwa/mesos,abudnik/mesos,verizonlabs/mesos,neilconway/mesos,zmalik/mesos,asamerh4/mesos,andschwa/mesos,zmalik/mesos,Aman-Jain-14/customizedMesos,Aman-Jain-14/customizedMesos,yuquanshan/customizedMesos,gsantovena/mesos