Merge pull request #15075 from edx/diana/reverse-back-arrow-rtl

Swap direction of arrow for RTL.

common/static/common/templates/sequence-breadcrumbs.underscore

 <% if (unifiedCourseView) { %>
     <a href="<%- '/courses/' + courseId + '/course/#' + blockId %>">
-        <span class="fa fa-arrow-circle-left" aria-hidden="true" aria-describedby="outline-description"></span>
+        <span class="fa fa-arrow-circle-prev icon" aria-hidden="true" aria-describedby="outline-description"></span>
         <span class="sr-only" id="outline-description"><%- gettext('Return to course outline') %></span>
         <b><%- gettext('Outline') %></b>
     </a>

lms/static/sass/course/base/_extends.scss

@@ -203,3 +203,13 @@ h1.top-header {
     }
   }
 }
+
+.fa-arrow-circle-prev {
+  &:before {
+    @if $bi-app-direction == ltr {
+        content: "\f0a8"; // .fa-arrow-circle-left
+    } @else if $bi-app-direction == rtl {
+        content: "\f0a9"; // .fa-arrow-circle-right
+    }
+  }
+}