examples: Use single up-to-date android example

[leomeinel]

Objective

• Only use a single modern and better documented android example

Problems with current examples

• We are currently using deprecated functions like for example setSystemUiVisibility(int).
• Most Android dependencies are very out of date.
• Kotlin is the preffered language for Android and we should migrate the examples to it.
• Most of the code in the examples is not inherently clear and there are very few comments especially in the build scripts.
• We should only have a single Android example using games-activity and cargo-ndk. It is confusing and unnecessary to do it any other way in my opinion.

Solution

• Replace all android examples with ./examples/mobile/android
• Update dependencies in libs.versions.toml
• Add gradle-daemon-jvm.properties generated with ./gradlew updateDaemonJvm.
• Update gradle wrapper
• Migrate everything to kotlin/kotlin build scripts
• Use supported functions instead of deprecated ones
• Move /assets/android-res/mipmap-mdpi/ic_launcher.png to /examples/mobile/android/app/src/main/res/mipmap/ic_launcher.png because that is where it is located by default.
• Use targetSdk = 36 and compileSdk = 36 and explain in examples/README.md

Testing

This currently builds successfully with cargo-ndk with the following commands:

cd ./examples/mobile
cargo ndk build -t aarch64-linux-android -o ./android/app/src/main/jniLibs

Afterwards you can build it with gradle like this or just use Android Studio:

cd ./android
./gradlew build

Current problems

Unrelated regression

Regression from #23551

Crashes if built without --release flag on x86_64. This seems to be only related to the change in android-activity version.

I have added a note to README.md for this.

Related

• Add modern Android example using `cargo-ndk` that uses kotlin and kotlin build scripts #22597

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[Litttlefish]

glad to see updates on android!

I just followed the java one before when I was making that update though, I'm favor to kotlin too

for libc++_shared, iirc it's required for oboe crate instead of rodio

also about --link-libcxx-shared flag, I think this doesn't work well with bevy, only the trick in the current example worked

[beicause]

I believe --link-libcxx-shared is not needed. See #23548.

[beicause]

nit: chmod +x is not needed. I can confirm the permissions of gradlew file you commited is 755 on linux.

[leomeinel]

Thank you for the review. I'll add a fixup commit that omits it. I just forgot to not include it 👍

If anyone wants the file to have 644 permissions instead, I can alternatively just do that.

[leomeinel]

Tested in Android studio emulator and working.

[mockersf]

We should only have a single Android example using games-activity and cargo-ndk. It is confusing and unnecessary to do it any other way in my opinion.

I don't agree with this. The differences between examples are meaningful and should be shown somewhere. I would prefer better documentation than just removing them

[leomeinel]

I don't agree with this. The differences between examples are meaningful and should be shown somewhere. I would prefer better documentation than just removing them

I could add a diff of MainActivity.kt to the readme, would that be okay with you?

[leomeinel]

Both regressions are now unrelated to this.

[beicause]

I think it's a good cleanup and tend to keep only one example (the native activity example is almost a duplicate). Actually I've never tested the other two examples. For users who want to try other approaches, android-activity and cargo-apk repositories have some examples, too. They might be worth mentioning but we lack testing.

Additionally, this PR will resolve the 16kb compatibility issue (See the screenshots of Android 16.0 / Samsung Galaxy S26 in https://bevyengine.github.io/bevy-example-runner). Already fixed since rodio update?