as i just told you: trying to publish an app with location services on play is going to be a problem.
i don't mean to speak for the author of the ultimatewebviewlibrary, but access to background location is specifically mentioned in the library when some website wants to know your location. the user is then prompted to grant permission to the website permission. that's the rule. perhaps the author is away on holiday; i'm sure he'll see the thread soon. hang on until then.
a prompt for location permission is definitely required by a webview. usually coarse or fine access. if, in fact, background access permission does not have to be prompted for, i'm sure he can do something for you.
if google's code police have seen a reference to background location, i'm guessing it must be in the library. or maybe some other library you use. member golubovic should appear soon.