Switch Android emulators from macOS runners to Ubuntu runners

[karlhorky]

Android tests are failing on macos-14 runners, seemingly because GitHub Actions macos-14 runners with M1 chips do not support running Android emulators:

• Update dependency macos to v14 - abandoned #212 (comment)

We could consider moving to Ubuntu, which may support Android emulators - apparently it's not complex to install the Android emulator, and there is a relatively short runtime installation time:

SDKMANAGER=${ANDROID_SDK_ROOT}/cmdline-tools/latest/bin/sdkmanager
echo "y" | ${SDKMANAGER} "tools"

• Add Android emulator on Ubuntu2204 actions/runner-images#9219 (comment)

Caveats

Since we're considering switching from Detox to Maestro, this may be irrelevant:

• Switch from Detox to Maestro? #106