SSSD does not translate the 2FA text labels("first factor" / "second factor") on GDM login based on the system locale.

Issue

• When using the 2Factor Authentication on RHEL7.6 machines in combination with sssd, gdm and GNOME3 desktop(using yubikeys),
  the user is prompted for "First Factor" and "Second Factor" when logging in or when unlocking a previously locked desktop.

• In contrast with all other Textlabels on the Login Screen (and Unlock Screen respectively) the two Labels provided for the credential
  Textfields are not translated (into German) but rendered in English.

• These labels should be translated based on the locale set by the user.

  Expected Label Text for a German user:
  
  "First Factor" should be "Passwort"
  "Second Factor" should be "OTP Token"