Reason for revert: Two of the machines are back. They were offline due to extended maintenance work needed. Original issue's description: > Remove android_rel from CQ since all of its machines are offline. > > BUG=558213 > TBR=phoglund@webrtc.org > > Committed: https://crrev.com/392d0c2701ef0112035e496cafcd2e7f0453547f > Cr-Commit-Position: refs/heads/master@{#10704} TBR=phoglund@webrtc.org NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true BUG=558213 Review URL: https://codereview.webrtc.org/1454883004 Cr-Commit-Position: refs/heads/master@{#10705}