android studio cannot resolve symbol 'GradleException'

The latest Android SDK does not support GradleException(), instead use FileNotFoundException().

Or for future readers, maybe use RuntimeException (if the issue is not file related).

I found the issue and the solution on this GitHub thread:
https://github.com/flutter/flutter/issues/29608

This was the solution for me: using

FileNotFoundException()

instead of

GradleException()

Note: this answer is no longer up-to-date for newer versions of Android Studio and Gradle. See this answer instead.

Android Studio seems to have various problems that I cannot understand why exist, but they're fixed by invalidating the caches and restarting (from the file menu item). Because the code compiles fine, it seems that this is one of those cases, in which a cache entry somehow ends up, I'm not really sure what specifically happens, but essentially something that prevents it from working properly.

So invalidating the caches and restarting may issues like this, whether it's with Gradle or with Java/Kotlin/Scala/<insert language here>.