FilesInUse_xx.rc should be in native encoding

In fix 6675949: [WAT] install fails trying to display Close Applications dialog (FilesInUse) on Vista, deployment team reorg the resource files, moving most of the contents in src/plugin/win32/regutilsmsi/RegUtilsMSI_xx.rc to src/plugin/win32/filesinuse/FilesInUse_xx.rc, but the contents are not saved in native encoding, which caused the content in non-english rc to be garbled.

The message porting should be redone to make sure non-english contents are saved in correct encoding.