Normalise feature set of Android build script with other platform builders

[freakboy3742]

The Android build script has a couple of minor differences to the iOS and Emscripten build scripts that are relatively easy to accomodate:

• The build target only allows you to to specify a host, not build or hosts or all
• The clean target doesn't have allow you to specify a host at all, so you can't delete all host builds without also deleting the build python, or clean a single host (at least, not with the clean command)
• The cache folder for downloads isn't configurable
• The cross-build directory isn't configurable.

We should aim for feature parity and consistency of UI between these scripts, wherever possible.

Linked PRs

• gh-146450: Normalise feature set of Android build script with other platform build scripts #146451

[akanil18]

Hi @freakboy3742, I would love to work on this issue!

To achieve feature parity and UI consistency with the iOS and Emscripten build scripts, here is my proposed approach:

1. build target: Update the argument parsing logic in the Android build script to accept build, hosts, and all as valid targets alongside specific hosts.
2. clean target: Modify the clean command to accept an optional host argument, allowing users to selectively clean specific host builds, all host builds, or the build python without wiping everything.
3. Configurable Directories: Introduce CLI flags (and environment variable fallbacks, if applicable) for configuring both the download cache folder and the cross-build directory. I will review the iOS and Emscripten build scripts first to ensure the argument naming conventions exactly match.

If this approach looks good to you, could you please assign this issue to me? I'll get started on a PR right away.

[freakboy3742]

@akanil18 The issue is already assigned to me, and there's already an open PR.

I would also note that this has all the hallmarks of an AI-generated response that is only repeating the information that is in the original ticket. This sort of comment isn't helpful, as it doesn't add anything to the conversation.