fix: Fix crash, show invalid track message instead (fossasia#2346)

* fix fossasia#2343: Fix crash, show invalid track message instead

* fix fossasia#2343: Fix crash with null check on Track

Author: pulakdp

android/app/src/main/java/org/fossasia/openevent/core/track/session/SessionDetailActivity.java

@@ -54,6 +54,7 @@
 import org.fossasia.openevent.data.Session;
 import org.fossasia.openevent.data.Speaker;
 import org.fossasia.openevent.data.Track;
+import org.fossasia.openevent.data.repository.RealmDataRepository;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -154,6 +155,11 @@ public void onCreate(final Bundle savedInstanceState) {
             if(session == null)
                 return;
 
+            if (RealmDataRepository.isNull(session.getTrack())) {
+                Snackbar.make(speakersRecyclerView, R.string.invalid_track, Snackbar.LENGTH_SHORT).show();
+                return;
+            }
+
             if(session.getIsBookmarked()) {
                 Timber.tag(TAG).d("Bookmark Removed");
 

android/app/src/main/res/values/strings.xml

@@ -152,6 +152,7 @@
     <string name="error">Error</string>
     <string name="http_error">HTTP Error</string>
     <string name="api_not_found">API Not Found</string>
+    <string name="invalid_track">Invalid track</string>
 
     <string name="empty_list">No Bookmarks Available</string>
     <string name="bullet">"•"</string>