Cherry-pick to 7.x: [CI][flaky] Support 7.x branches and PRs (#22197)#22229

Merged

v1v merged 1 commit intoelastic:7.xfrom v1v:backport/7.x/pr-22197

Oct 28, 2020

+28-2

Commits on Oct 28, 2020

[CI][flaky] Support 7.x branches and PRs (elastic#22197 )
v1v
committed