Fix crash in emulator launch in android-emulator-tests.sh

[marcprux]

While waiting for the Android emulator to start up, we poll it with adb wait-for-any-device. This seems to crash sometimes (e.g, in this workflow run for apple/swift-configuration#140) with:

USER_INFO    | Emulator is performing a full startup. This may take upto two minutes, or more.
WARNING      | Failed to process .ini file /home/runner/.android/emu-update-last-check.ini for reading.
timeout: the monitored command dumped core
/home/runner/work/swift-configuration/swift-configuration/github-workflows/.github/workflows/scripts/android/android-emulator-tests.sh: line 99:  6236 Aborted                 timeout "${ANDROID_EMULATOR_TIMEOUT}" adb wait-for-any-device
WARNING      | Failed to process .ini file /home/runner/.android/emu-update-last-check.ini for reading.

This PR introduces periodic polling with adb shell getprop sys.boot_completed on the theory that the emulator startup process is conflicting with the adb command.

An example of the output should now look like:

** Waiting for Android emulator startup (5)
* daemon not running; starting now at tcp:5037
* daemon started successfully
adb: device offline
** Waiting for Android emulator startup (10)
** Waiting for Android emulator startup (15)
** Waiting for Android emulator startup (20)
** Waiting for Android emulator startup (25)
** Waiting for Android emulator startup (30)
** Waiting for Android emulator startup (35)
INFO         | Boot completed in 38815 ms
INFO         | Increasing screen off timeout, logcat buffer size to 2M.
** Waiting for Android emulator startup (40)
** Emulator is ready
** Prepare Swift test package

CC: @finagolfin

[marcprux]

Oops, this might conflict with the delay introduced in #221. Converting to draft while I inquire…

[marcprux]

The new adb start-server call added in PR #221 is now crashing:

USER_INFO    | Emulator is performing a full startup. This may take upto two minutes, or more.
WARNING      | Failed to process .ini file /home/runner/.android/emu-update-last-check.ini for reading.
/home/runner/work/swift-configuration/swift-configuration/github-workflows/.github/workflows/scripts/android/android-emulator-tests.sh: line 99:  6111 Aborted                 (core dumped) adb start-server

(before it was crashing with adb wait-for-any-device)

Maybe we can introduce a delay before calling any adb operation?

[marcprux]

BTW, @justice-adams-apple, why did you add adb start-server? I haven't experienced that it was necessary in the past…

[marcprux]

The way that ReactiveCircus/android-emulator-runner deals with this is to continually poll adb -s emulator-${port} shell getprop sys.boot_completed. Maybe that's the way to go…

[finagolfin]

I was wondering how you got away with not doing that, as even that polling has failed in the past, its error rate is just lower...

[marcprux]

Can someone add this to the "In Progress" for the Swift on Android project board?

[marcprux]

OK, I think this is ready to go.

@finagolfin and @justice-adams-apple, if you want to test this out prior to it being merged, I think you should be able to test it with:

-    uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
+    uses: swift-android-sdk/github-workflows/.github/workflows/swift_package_test.yml@android-sleep-before-adb

[marcprux]

if you want to test this out prior to it being merged, I think you should be able to test it with:

Derp, nevermind. I see it isn't allowed:

Error
The reusable workflow swift-android-sdk/github-workflows/.github/workflows/swift_package_test.yml@android-sleep-before-adb is not allowed in apple/swift-configuration because all reusable workflows must be from a repository owned by your enterprise or match one of the patterns…

We'll need to wait for this to be merged before we can really exercise it.

[justice-adams-apple]

LGTM

[marcprux]

Can someone merge this please, @swiftlang/github-workflows-contributors ? I don't have permission…