TF-1683 Remove Plain text option of message in VacationView

(cherry picked from commit 9a6f9b2ecaf629140f0676bff1a33e524f17ebc1)

lib/main/localizations/app_localizations.dart

@@ -1250,12 +1250,6 @@ class AppLocalizations {
         name: 'signature');
   }
 
-  String get plain_text {
-    return Intl.message(
-        'Plain text',
-        name: 'plain_text');
-  }
-
   String get html_template {
     return Intl.message(
         'Html template',

lib/main/utils/app_utils.dart

@@ -33,8 +33,7 @@ class AppUtils {
     return intl.Bidi.isRtlLanguage(Localizations.localeOf(context).languageCode);
   }
 
-  static TextDirection getCurrentDirection(BuildContext context) =>
-    isDirectionRTL(context) ? TextDirection.rtl : TextDirection.ltr;
+  static TextDirection getCurrentDirection(BuildContext context) => Directionality.maybeOf(context) ?? TextDirection.ltr;
 
   static bool isEmailLocalhost(String email) {
     return  RegExp(r'^(([^<>()[\]\\.,;:\s@"]+(\.[^<>()[\]\\.,;:\s@"]+)*)|(".+"))@localhost$').hasMatch(email);