Bump minimum emulator to API Level 23.

This has been Google's typical minimum supported level, such as [in AndroidX](https://issuetracker.google.com/issues/380448311).

Also, switch emulator tests to Ubuntu with KVM, as [recommended nowadays](https://github.com/marketplace/actions/android-emulator-runner#running-hardware-accelerated-emulators-on-linux-runners).

RELNOTES=n/a
PiperOrigin-RevId: 857192485

Author: cpovirk

.github/actions/artifact-android-emulator-tests/action.yml

@@ -9,6 +9,12 @@ inputs:
 runs:
   using: "composite"
   steps:
+    # https://github.com/marketplace/actions/android-emulator-runner#running-hardware-accelerated-emulators-on-linux-runners
+    - 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: 'Check out repository'
       uses: actions/checkout@v4
     - name: 'Cache Gradle files'

.github/workflows/ci.yml

@@ -87,12 +87,10 @@ jobs:
     # can take a while to run
     if: github.event_name == 'push' && github.repository == 'google/dagger' && github.ref == 'refs/heads/master'
     needs: bazel-build
-    # It's recommended to run emulator tests on macOS
-    # See https://github.com/marketplace/actions/android-emulator-runner
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     strategy:
-      matrix: # Run on 16 (PreL), 21 (L), and 26 (O).
-        api-level: [16, 21, 26, 30]
+      matrix:
+        api-level: [23, 26, 30]
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/artifact-android-emulator-tests