Bump Android commandline tools from 12.0 to 19.0

[rmartin16]

Changes

• Use latest (v19.0) version of Android's commandline tools
• This will cause Briefcase to install this version of commandline tools alongside v12.0

Notes

• They're really moving through the versions it seems now...
  

PR Checklist:

• All new features have been tested
• All new features have been documented
• I have read the CONTRIBUTING.md file
• I will abide by the code of conduct

[rmartin16]

hmm....so in the middle of testing this, I started getting this error:

[helloworld] Building Android APK...

> Configure project :app
Warning: Python version 3.12 may have fewer packages available. If you experience problems, try switching to version 3.8.

> Task :app:preBuild UP-TO-DATE
> Task :app:preDebugBuild UP-TO-DATE
> Task :app:mergeDebugNativeDebugMetadata NO-SOURCE
> Task :app:extractDebugPythonBuildPackages UP-TO-DATE
> Task :app:generateDebugPythonRequirements FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:generateDebugPythonRequirements'.
> Couldn't find Python. See https://chaquo.com/chaquopy/doc/current/android.html#buildpython

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.
> Get more help at https://help.gradle.org.

BUILD FAILED in 459ms
2 actionable tasks: 1 executed, 1 up-to-date
Building... errored

Error while building project.

I don't think this issue is related to these changes....but I'm also not sure why this is happening.

Nonetheless, can you please verify this new version is working for you?

[freakboy3742]

@rmartin16 Worked for me first time... not sure what happened in your run. Being unable to find Python is an odd one... any ideas @mhsmith?

[rmartin16]

I'm having trouble replicating this issue now....but I do feel pretty confident that whatever was happening is unrelated to these changes.

[mhsmith]

Chaquopy's discovery of a Python executable can be confusing, because the Gradle daemon doesn't reliably update its PATH when it's reused (gradle/gradle#10483). So a Gradle build launched from the command line may end up using the PATH of an Android Studio instance, or vice versa. Killing all Gradle daemons and trying again should resolve the problem.

But I agree that issue probably doesn't have anything to do with this PR.