chore: explicitly drop to jdk 17

[MustafaHaddara]

Which problem is this PR solving?

While working on #24, I noticed Android Studio had updated the compiler config in the .idea directory to drop down to java compiler 17 (instead of 21).

Similarly, I started seeing warnings like

> Task :core:compileDebugJavaWithJavac
Java compiler version 21 has deprecated support for compiling with source/target version 8.
Try one of the following options:
    1. [Recommended] Use Java toolchain with a lower language version
    2. Set a higher source/target version
    3. Use a lower version of the JDK running the build (if you're not using Java toolchain)
For more details on how to configure these settings, see https://developer.android.com/build/jdks.
To suppress this warning, set android.javaCompile.suppressSourceTargetDeprecationWarning=true in gradle.properties.
warning: [options] source value 8 is obsolete and will be removed in a future release
warning: [options] target value 8 is obsolete and will be removed in a future release
warning: [options] To suppress warnings about obsolete options, use -Xlint:-options.
3 warnings

(job link)

The documentation for the CircleCI Android orb implies that Java 17 is the default but clearly it's actually using Java 21.

Short description of the changes

This PR updates our CircleCI config to explicitly use 17, and commits the updated Android Studio config to keep local dev environments in line.

How to verify that this has the expected result

The same job no longer spits out the Java compiler version 21 warning