Try to switch running tests from MacOS to Linux

.github/workflows/build.yaml

@@ -17,11 +17,16 @@ jobs:
 
   android_tests:
     # see https://github.com/reactivecircus/android-emulator-runner,
-    # needs to run on macos as only there virtualization is available!
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
 
+      - name: Enable KVM group perms
+        run: |
+          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
+          sudo udevadm control --reload-rules
+          sudo udevadm trigger --name-match=kvm
+
       - name: Set up JDK
         uses: actions/setup-java@v2
         with:
@@ -32,5 +37,4 @@ jobs:
         uses: reactivecircus/android-emulator-runner@v2
         with:
           api-level: 26
-          arch: arm64-v8a
           script: ./gradlew connectedCheck