rerun upm tests for sporadic failures (#4437)

.yamato/com.unity.ml-agents-test.yml

     flavor: {{ platform.flavor}}
   commands:
     - npm install upm-ci-utils@stable -g --registry https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
-    - upm-ci project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ coverageOptions }}
+    - upm-ci project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ coverageOptions }} --extra-utr-arg "reruncount=2"
     {% if editor.enableCodeCoverage %}
     - python3 ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ package.minCoveragePct }}
     {% endif %}
     - python -m pip install unity-downloader-cli --index-url https://artifactory.prd.it.unity3d.com/artifactory/api/pypi/pypi/simple --upgrade
     - unity-downloader-cli -u trunk -c editor --wait --fast
     - npm install upm-ci-utils@stable -g --registry https://artifactory.prd.cds.internal.unity3d.com/artifactory/api/npm/upm-npm
-    - upm-ci project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ coverageOptions }}
+    - upm-ci project test -u {{ editor.version }} --project-path Project --package-filter {{ package.name }} {{ coverageOptions }} --extra-utr-arg "reruncount=2"
     {% if editor.enableCodeCoverage %}
     - python3 ml-agents/tests/yamato/check_coverage_percent.py upm-ci~/test-results/ {{ package.minCoveragePct }}
     {% endif %}