CLDR-11368 Enable Forum posting by TC even when read-only (unicode-or…

…g#2754)

-Revise SurveyForum.userCanUsePostType, isPhaseReadonly only matters for non-TC

-Refactor with boolean isTC to avoid calling userIsTC repeatedly

tools/cldr-apps/src/main/java/org/unicode/cldr/web/SurveyForum.java

@@ -272,13 +272,14 @@ private void gatherUsersInterestedInThread(PostInfo postInfo, User currentUser,
      * @return true or false
      */
     private boolean userCanUsePostType(PostInfo postInfo) {
-        if (SurveyMain.isPhaseReadonly()) {
+        User user = postInfo.getUser();
+        boolean isTC = UserRegistry.userIsTC(user);
+        if (!isTC && SurveyMain.isPhaseReadonly()) {
             return false;
         }
         int replyTo = postInfo.getReplyTo();
         PostType postType = postInfo.getType();
-        User user = postInfo.getUser();
-        if (postType == PostType.DISCUSS && replyTo == NO_PARENT && !UserRegistry.userIsTC(user)) {
+        if (postType == PostType.DISCUSS && replyTo == NO_PARENT && !isTC) {
             return false; // only TC can initiate Discuss; others can reply
         }
         if (postType != PostType.CLOSE) {
@@ -290,7 +291,7 @@ private boolean userCanUsePostType(PostInfo postInfo) {
         if (getUserId(postInfo.getRoot()) == user.id) {
             return true;
         }
-        return UserRegistry.userIsTC(user);
+        return isTC;
     }
 
     /**