Disable flaking #testMIDIDialog.

Bug: 330692957
Change-Id: Idf3cab84fa83bc8b80d3286ec47a713f3dbf7389
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5411219


Commit-Queue: Sky Malice <skym@chromium.org>
Auto-Submit: Sky Malice <skym@chromium.org>
Owners-Override: Sky Malice <skym@chromium.org>
Reviewed-by: Brandon Wylie <wylieb@google.com>
Cr-Commit-Position: refs/heads/main@{#1280926}