Hide chrome and default_tab from advanced settings

It doesn't make sense to list these LMS block attributes in course-level advanced settings. Doing so is confusing to course teams.

cms/djangoapps/models/settings/course_metadata.py

@@ -50,7 +50,9 @@ class CourseMetadata(object):
         'is_time_limited',
         'is_practice_exam',
         'exam_review_rules',
-        'self_paced'
+        'self_paced',
+        'chrome',
+        'default_tab',
     ]
 
     @classmethod

common/test/acceptance/pages/studio/settings_advanced.py

@@ -184,9 +184,7 @@ class AdvancedSettingsPage(CoursePage):
             'display_coursenumber',
             'display_organization',
             'catalog_visibility',
-            'chrome',
             'days_early_for_beta',
-            'default_tab',
             'disable_progress_graph',
             'discussion_blackouts',
             'discussion_sort_alpha',