fix: CourseUnitNavigationActivity resume crashes after free up

resources.

- App crashes when the user resumes the app when memory is low and the
user tries to change the unit/component through the next/previous buttons
or swipe left/right, to fix these issues store state using
`onSaveInstanceState`, and restore state on `onRestoreInstanceState` to
make sure the availability of data.

fixes:
- LEARNER-8984
- LEARNER-8985

OpenEdXMobile/src/main/java/org/edx/mobile/view/CourseBaseActivity.java

@@ -100,6 +100,7 @@ public void onSaveInstanceState(Bundle outState) {
     }
 
     protected void restore(Bundle savedInstanceState) {
+        blocksApiVersion = config.getApiUrlVersionConfig().getBlocksApiVersion();
         if (savedInstanceState != null) {
             courseData = (EnrolledCoursesResponse) savedInstanceState.getSerializable(Router.EXTRA_COURSE_DATA);
             courseUpgradeData = savedInstanceState.getParcelable(Router.EXTRA_COURSE_UPGRADE_DATA);
@@ -115,7 +116,6 @@ protected void restore(Bundle savedInstanceState) {
      * Method to force update the course structure from server.
      */
     protected void updateCourseStructure(String courseId, String componentId) {
-        blocksApiVersion = config.getApiUrlVersionConfig().getBlocksApiVersion();
         getHierarchyCall = courseApi.getCourseStructureWithoutStale(blocksApiVersion, courseId);
         getHierarchyCall.enqueue(new CourseAPI.GetCourseStructureCallback(this, courseId,
                 new ProgressViewController(binding.loadingIndicator.loadingIndicator), errorNotification,