Bug 1407432 - Remove unused private/*.h system wrappers; r=froydnj

These don't actually install correctly, because 'private' is already a
system wrapper. Neither of these files are included anywhere, so there's
no harm in removing them.

MozReview-Commit-ID: 1IAFMZDvKDV

--HG--
extra : rebase_source : 6e153324d2add32a179d07020270db96e7ec6dd0

config/system-headers

@@ -851,10 +851,6 @@ PP_Resources.h
 PP_Types.h
 Printing.h
 Print/PMPrintingDialogExtensions.h
-#ifdef ANDROID
-private/android_filesystem_config.h
-private/qucomextra_p.h
-#endif
 Processes.h
 process.h
 Process.h