install importlib_metdata for 3.7

Author: Victoria Hall

eng/templates/jobs/build.yml

@@ -27,6 +27,9 @@ jobs:
       - bash: |
           python -m pip install -U pip
           python -m pip install build
+          if [[ $(PYTHON_VERSION) == "3.7" ]]; then
+              python -m pip install importlib_metadata
+          fi
           python -m build
         displayName: 'Build Python SDK for $(PYTHON_VERSION)'
       - bash: |