Prepare windmill.proto for output watermarks
Prepare windmill.proto for output watermarks

----Release Notes----
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=107257166

sammcveety/DataflowJavaSDK,apache/beam,yk5/beam,chamikaramj/beam,charlesccychen/beam,manuzhang/beam,robertwb/incubator-beam,markflyhigh/incubator-beam,dhalperi/incubator-beam,staslev/beam,jbonofre/beam,RyanSkraba/beam,robertwb/incubator-beam,nevillelyh/DataflowJavaSDK,wtanaka/beam,chamikaramj/beam,manuzhang/incubator-beam,dhalperi/incubator-beam,dhalperi/beam,tgroh/beam,elibixby/DataflowJavaSDK,amitsela/incubator-beam,RyanSkraba/beam,josauder/AOP_incubator_beam,apache/beam,lukecwik/incubator-beam,chamikaramj/beam,charlesccychen/beam,lukecwik/incubator-beam,lukecwik/incubator-beam,tgroh/beam,apache/beam,lukecwik/incubator-beam,jbonofre/beam,eljefe6a/incubator-beam,lukecwik/incubator-beam,apache/beam,rangadi/beam,markflyhigh/incubator-beam,joshualitt/DataflowJavaSDK,ravwojdyla/incubator-beam,amitsela/incubator-beam,ravwojdyla/incubator-beam,charlesccychen/incubator-beam,iemejia/incubator-beam,eljefe6a/incubator-beam,rangadi/beam,tweise/beam,dhalperi/beam,lukecwik/incubator-beam,chamikaramj/beam,wangyum/beam,wangyum/beam,chamikaramj/beam,markflyhigh/incubator-beam,manuzhang/beam,tgroh/beam,jasonkuster/beam,charlesccychen/beam,robertwb/incubator-beam,charlesccychen/incubator-beam,apache/beam,tgroh/incubator-beam,tweise/incubator-beam,rangadi/beam,apache/beam,charlesccychen/incubator-beam,tweise/incubator-beam,lukecwik/incubator-beam,tweise/beam,peihe/incubator-beam,markflyhigh/incubator-beam,rangadi/beam,jbonofre/beam,wangyum/beam,peihe/incubator-beam,mxm/incubator-beam,staslev/incubator-beam,joshualitt/incubator-beam,mxm/incubator-beam,yk5/beam,rangadi/beam,apache/beam,amitsela/beam,jbonofre/beam,chamikaramj/beam,chamikaramj/beam,amarouni/incubator-beam,josauder/AOP_incubator_beam,chamikaramj/incubator-beam,vikkyrk/incubator-beam,staslev/beam,apache/beam,jasonkuster/incubator-beam,robertwb/incubator-beam,Test-Betta-Inc/musical-umbrella,apache/beam,lukecwik/incubator-beam,jbonofre/incubator-beam,joshualitt/incubator-beam,rangadi/beam,tgroh/incubator-beam,wtanaka/beam,RyanSkraba/beam,xsm110/Apache-Beam,amarouni/incubator-beam,RyanSkraba/beam,robertwb/incubator-beam,rangadi/incubator-beam,charlesccychen/beam,iemejia/incubator-beam,sammcveety/incubator-beam,charlesccychen/beam,lukecwik/incubator-beam,chamikaramj/beam,staslev/beam,charlesccychen/beam,manuzhang/incubator-beam,peihe/DataflowJavaSDK,peihe/DataflowJavaSDK,chamikaramj/beam,sammcveety/incubator-beam,sammcveety/DataflowJavaSDK,staslev/incubator-beam,robertwb/incubator-beam,xsm110/Apache-Beam,lukecwik/incubator-beam,markflyhigh/incubator-beam,charlesccychen/beam,manuzhang/beam,vikkyrk/incubator-beam,joshualitt/DataflowJavaSDK,dhalperi/beam,ravwojdyla/incubator-beam,elibixby/DataflowJavaSDK,wtanaka/beam,markflyhigh/incubator-beam,Test-Betta-Inc/musical-umbrella,amitsela/beam,vikkyrk/incubator-beam,amitsela/beam,RyanSkraba/beam,chamikaramj/beam,wangyum/beam,rangadi/incubator-beam,rangadi/beam,robertwb/incubator-beam,peihe/incubator-beam,apache/beam,eljefe6a/incubator-beam,markflyhigh/incubator-beam,RyanSkraba/beam,robertwb/incubator-beam,jbonofre/incubator-beam,tgroh/beam,yk5/beam,jasonkuster/beam,jasonkuster/incubator-beam,sammcveety/incubator-beam,xsm110/Apache-Beam,rangadi/incubator-beam,jasonkuster/beam,chamikaramj/incubator-beam,apache/beam,robertwb/incubator-beam,robertwb/incubator-beam,RyanSkraba/beam