Removed redundant 'Times(1)' from master validation tests.
Removed redundant 'Times(1)' from master validation tests.

This patch removes calls to `.Times(1)` from `EXPECT_CALL`
invocations in the master validation tests because it is
redundant.

Review: https://reviews.apache.org/r/56139/

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