As you may know, the Android development system is available for the Raspberry Pi from the Debian project here: https://packages.debian.org/buster/android-sdk However, they do not include Android Studio. Is there a good tutorial on how to develop Android apps on the Pi without Android Studio?
After you install the Android SDK, you can open the SDK Manager and install the tools and Android APIs. Then you can install Eclipse with
sudo apt-get install eclipse. After you install a plug-in called Android Development Tools (ADT), you should have a normal development experience. One aspect of the development that might be different is the testing process. Because the Pi isn't powerful enough to run an Android emulator, you'll have to build the whole app and install it on an actual device every time you want to test your app. Another issue with this method would be the fact that Eclipse isn't lightweight and you might have issues with less powerful Pis.
Android programming is not possible natively on the Raspberry Pi, because the various Android packages do not include the SDK manager which is needed to download related software. The SDK manager is now a part of Android Studio which has not been ported to the Pi.
However there is one way to build Android apps on the Pi, by using Qemu to emulate an x86_64 running any x86 Linux distro and then installing the x86 Android Studio in that. It is very slow but it seems to work. This is a case where it might be wise to overclock the Pi, and you should run Qemu with the -smp option to specify multiple cores.