Remove unused steps from build process

[tlmii]

A couple of small build tweaks here:

• Arcade updated their scripts so you can configure it to only publish the xunit test results and not the trx test results. We just need to swap out enablePublishTestResults: true (which will publish both) for testResultsFormat: xunit (which will only publish xunit results. This will get rid of the build warnings we had (one per platform per configuration)
• The enablePublishUsingPipelines: true parameter wasn't needed for what we're doing in our builds
• We were publishing the log files twice under slightly different container names - once in our build steps and then again in the Arcade templates.