Skipped tests when verifying `master` as part of review verification.
Skipped tests when verifying `master` as part of review verification.

Due to flakes test results reported by reviewbot need manual
verification so we can skip executing tests when validating the
`master` branch. This saves some execution time during validation.

Incidentally with this patch a previous comment matches now matches
what is happening.

Review: https://reviews.apache.org/r/70045/

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