They still use zygote, however as expected, cheap Android devices aren't the best hardware to run an AOT compiler, so with Android 7 they introduced a multitier execution, with interpreter hand written in Assembly, JIT compiler and AOT that take advantage of PGO data.

The AOT compiler only runs when the device is idle.

Starting with Android 10, they introduced a mechanism to upload PGO data into the store, so that when an APK is installed, if such data is already available the JIT/AOT don't have to relearn everything from scratch regarding the application.

https://source.android.com/devices/tech/dalvik/jit-compiler

They also improved the GC several times, the latest generation is quite good,

https://source.android.com/devices/tech/dalvik/gc-debug

There are several Google IO talks about how they went through this.