[TTS] Mark testTapMultipleSwipeOnlyLoadsContentOnce as flaky

The test was already disabled to Android versions less than M, but it
started failing on M as well.

(cherry picked from commit 11f272cf357750f4f44dcac3e2b2dae3172bfd0a)

Bug: 1032955
TBR: donnd@chromium.org
Change-Id: I6dd62f0360ff3b3405d53fb8f80faea8ef47ffcf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1962065
Reviewed-by: Alex Ilin <alexilin@chromium.org>
Commit-Queue: Alex Ilin <alexilin@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#723787}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1978841
Reviewed-by: Donn Denman <donnd@chromium.org>
Commit-Queue: Donn Denman <donnd@chromium.org>
Cr-Commit-Position: refs/branch-heads/3987@{#321}
Cr-Branched-From: c4e8da9871cc266be74481e212f3a5252972509d-refs/heads/master@{#722274}
1 file changed