If you specify a “bundle_resources” path, you should point to a directory containing platform assets:
example.
In this folder, we will look for platform folders, and any files under there, will be copied (with relative paths) to the bundle (same for all platforms)
If you are talking about the “res” folder in a native extension, that folder too will have platform folders under it. And, on top of it, the Android build process dictates that actual resource files should be under yet another “res” folder. This is used for android resources (e.g. xm files, icons etc):
<extension>/res/android/res/draw/...
However, if you wish to put a binary file as-is, into the Android’s special assets folder, put it under the bundle_resources folder (e.g. “/res”:
<project>/res/android/assets/fmod_banks/master.bank