Adds .kotlin to Android.gitignore

[lissy93]

Link to the application or project's homepage

• https://developer.android.com/
• https://kotlinlang.org/ - (since kotlin is the default lang for android development now)
• https://gradle.org/- (already configured in this file, before my changes)

Reasons for making this change

Some of the Android's .gradle directory contents has now moved over to the .kotlin directory (since v 2.0.0). And the docs mention it needs to be gitignore'd alongside the .gradle.
This is already ignored in the Android's official .gitignore, but was missing here.

Links to documentation supporting these rule changes

• https://kotlinlang.org/docs/gradle-configure-project.html#kotlin-gradle-plugin-data-in-a-project
• https://github.com/android/nowinandroid/blob/main/.gitignore
• android/compose-samples@b2158b8

Merge and Approval Steps

• I have read the contribution guidelines and understand my PR will be closed if it doesn't meet these guidelines

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Updates the Android .gitignore template to exclude Kotlin tooling artifacts from version control.

Changes:

• Added .kotlin/ to ignored paths (Kotlin build/cache directory)

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