It seems that "Files to Commit:" is hardcoded. Please extract it to resource bundle.
org.openide.awt.Mnemonics.setLocalizedText(filesSectionButton, "Files to Commit:");
Integrated into 'main-golden', will be available in build *200904150201* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Ondrej Vrabec <firstname.lastname@example.org>
Log: #162494 -I18N : "Files to Commit:" is not from bundle
Thank you! Verified on build 200904180201.