Currently the Android team doesn't have any plans to expose Rust support on the NDK/AGK, anyone going down that path is expected to support themselves in Android Studio, Gradle, CMake, android-ndk, AAR/Bundles, JNI integration.
Nothing of that covers "Android Studio, Gradle, CMake, android-ndk, AAR/Bundles, JNI integration", which an Android shop expects to have out of the box support in the Android SDK installer.
Note that android-ndk in that comment means the original Makefile based build tooling, which CMake builds still lack some corner cases in functionality, hence why I listed both.
So, just to be clear, in what languages do I not need to "support myself" under your definition and what does the "support" consist of?
Do I get an Android test phone to try my software out? Is there like free phone support so I can chat to some expert in my language about Android problems? You make it sounds like a pretty big deal, but my small experience† of writing Android software a decade ago was that it just wasn't that hard.
† I wrote an implementation of the now obscure mOTP (similar to TOTP) for in-house usage. For obvious reasons I named This One Time app "Band Camp" which was already a pretty old reference at the time but once I thought of it I couldn't help myself.
I just tried this and... no C++. You can add the NDK and start building stuff with C++, but that's also exactly how the Rust offering works. If the result was actually a properly configured out of the box C++ development environment that would be pretty nice besides the Android stuff, but it isn't, the actual result out of the box is you get to pick Java or Kotlin.
You can do C++ native development for Android, but only via basically the same route as Rust, there's just not the huge gap you implied.