Fix NDK env var discrepancy in integration tests

.github/workflows/integration_tests.yml

@@ -79,7 +79,7 @@ jobs:
  - name: Add msbuild to PATH (windows)
  if: startsWith(matrix.os, 'windows')
  uses: microsoft/setup-msbuild@v1.0.1
- 
+
  - name: Cache vcpkg C++ dependencies
  if: matrix.target_platform == 'Desktop'
  id: cache_vcpkg
@@ -97,7 +97,7 @@ jobs:
  if: matrix.target_platform == 'Desktop'
  run: |
  python scripts/gha/install_prereqs_desktop.py
- 
+
  - name: Install SDK Android prerequisites
  if: matrix.target_platform == 'Android'
  shell: bash
@@ -108,27 +108,29 @@ jobs:
  if: matrix.target_platform == 'iOS'
  run: |
  build_scripts/ios/install_prereqs.sh
- 
+
  - name: Prepare for integration tests
  run: |
  pip install -r scripts/gha/requirements.txt
  python scripts/gha/restore_secrets.py --passphrase "${{ secrets.TEST_SECRET }}"
- 
+
  - name: Build integration tests (and run Desktop tests)
  # The set up script for Android will download the NDK here.
- env:
-  NDK_ROOT: '/tmp/android-ndk-r16b'
+ # Need to export from bash, so that /tmp gets converted on Windows.
+ shell: bash
  run: |
+ export NDK_ROOT=/tmp/android-ndk-r16b
+ export ANDROID_NDK_HOME=/tmp/android-ndk-r16b
  python scripts/gha/build_testapps.py --t ${{ github.event.inputs.apis }} --p ${{ matrix.target_platform }} --output_directory ${{ github.workspace }} --use_vcpkg --execute_desktop_testapp --noadd_timestamp
- 
+
  # Workaround for https://github.com/GoogleCloudPlatform/github-actions/issues/100
  # Must be run after the Python setup action
  - name: Set CLOUDSDK_PYTHON (Windows)
  if: startsWith(matrix.os, 'windows') && !cancelled()
  run: echo "::set-env name=CLOUDSDK_PYTHON::${{env.pythonLocation}}\python.exe"
  - name: Install Cloud SDK
  if: ${{ !cancelled() }}
- uses: GoogleCloudPlatform/github-actions/setup-gcloud@master 
+ uses: GoogleCloudPlatform/github-actions/setup-gcloud@master
  - name: Upload Desktop Artifacts to GCS
  if: matrix.target_platform == 'Desktop' && !cancelled()
  run: |