GitLab

Updated bot summary logging for xcodebuild_runner.

Do the same logging as test_runnner:
- show flaky/failed tests in bot summary
- display stacktrace for each failure and each attempt
- removed xcodebuild command from bot summary
- changed print -> logging

For non_started_tests case add `Message` from ErrorSummaries

The examples of log:
https://ci.chromium.org/p/chromium/builders/try/ios12-sdk-simulator/241
https://ci.chromium.org/p/chromium/builders/try/ios12-sdk-simulator/249

Bug: 912323
Change-Id: Ie48cf020db31ff2229a1e5a5be05f1ed651a1c0a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1495440Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Commit-Queue: Maksym Onufriienko <monufriienko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644423}