Add modern Android example using cargo-ndk that uses kotlin and kotlin build scripts

[leomeinel]

Hello, I'm making this as a starting point for later creating a PR but I think that getting some feedback here before would be quite useful.

Current problems

• We are 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• Most Android dependencies are very out of date.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. I've definetly had problems trying to understand which example I should follow.
• The crash from Unable to run mobile example on Android emulator #10945 is fixed by migrating to games-activity 4, we are using games-activity 2. (Android) Touch events not working #17122 is apparently also fixed.

Solution

This solution currently has to wait until android-activity releases a version compatible with games-activity 4. This discussion has some details on when that might happen. It would however be possible to stick with games-activity 2 and agp 8.

• I have ported my own game that I'm using to learn bevy to Android recently and am using only up-to-date dependencies and have rewritten everything with non-deprecated functions. I could easily submit a PR after android-activity has a new release. See the crates' Cargo.toml and my mobile/android for details.

Additional details

To get around the android-activity problem, we could also just do something similar to this, which was also mentioned in #17122, I wouldn't deem this a good solution though, only a very temporary workaround.