Don't upload/download the developer config file if it's a local project

What this patch does, is to not have a developerTempFile and instead use
the actual developer config file (the .kdev4/*.kdev4) to read/write
configurations, in case it's a local project. This way we skip the download
part and kconfig will edit the file in place.

BUG: 291983
REVIEW: 109317