Upgrade dexmaker to AGP 8.5

[prashanthswami]

The intent of this change is to migrate to Android Gradle Plugin 8.5.0, but as a consequence introduces a few other changes:

• The minimum viable SDK is now 21, as NDK r26 dropped support for 19.
• The minimum Gradle version is now 8, as AGP 8.5.0 requires it.
• The minimum JDK version is now 17, as AGP 8.5.0 requires it.
• The errorprone library was upgraded to provide new JDK classes.
• The publishing scripts were updated to use the new Gradle properties.
• Errorprone fixes were applied to the inline-extended classes.

[prashanthswami]

Hello! To provide some context for this change - I'm from Google, working on the Android RISC-V project (https://github.com/google/android-riscv64). We recently landed support to build against the RISC-V ABI in the Android NDK (r27), and we're now starting to walk through all the libraries internally that we'd like to produce RISC-V artifacts for - in turn, we're looking at dependencies like dexmaker that AndroidX needs to produce it's own artifacts.

I'd like to file a separate issue to get the maintainer's thoughts on how feasible it would be to publish RISC-V artifacts, but a prerequisite to even consider RISC-V is migrating to an AGP version that supports it. As upgrading AGP versions is orthogonal, I'm hoping we can enable AGP 8.5 with this change and consider RISC-V in a follow up PR.