Resync group and passwd files when creating user.
Resync group and passwd files when creating user.

If a unit is rebooted while creating app users, the group and passwd files
can get out of sync and the app group can exist without the user (or possibly
visa versa).  Recover gracefully from this case by changing the user/group
creation to create the user/group if it doesn't exist, otherwise return
the existing user/group id.

Resolves: LE-7002
Change-Id: I099df9285f653f6b9fde3fe3d300d35f2b1a793f

legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af,legatoproject/legato-af