[ews] Use SetBuildSummary instead of buildFinished in Layout tests to set custom build summary. buildFinished() method finishes the build immediately, while it might not be desirable in some cases/factories. We added SetBuildSummary build step in https://bugs.webkit.org/show_bug.cgi?id=207026 for this purpose. We are using that for webkitpy tests. We should start using that that in layout-tests as well.
Created attachment 390282 [details] Patch
Sample runs: No failures: https://ews-build.webkit-uat.org/#/builders/16/builds/76 Flaky failures: https://ews-build.webkit-uat.org/#/builders/16/builds/80 pre-existing test failures: https://ews-build.webkit-uat.org/#/builders/16/builds/82
Committed r256206: <https://trac.webkit.org/changeset/256206>
<rdar://problem/59322779>