How do I get Android Studio to stop returning generated code in search results?

The way I've been doing to ignore generated classes in advanced search is adding !file:*intermediates*/&&!file:*generated*/&&!lib:*..* to a new Custom Scope, like this:

14-October-2015 Update: I have improved the pattern by also excluding the !lib:*..* from the search. Thanks.

I've seen this in IntelliJ, haven't checked in Android Studio. But when you do find in path (via ctrl+shift+F) there's a "File name filter" section in the search popup which has a checkbox called "File masks" which you might be able to filter desired file types.

For me, just to add to the answer, the scope !file:*intermediates*/&&!file:*generated*/&&!file:*build*/&&!lib:*..* worked even better!