Change 'tab_bookmarks' string to 'Bookmarked Playlists' for UI clarity

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

@@ -34,7 +34,7 @@
 
     <string name="tab_main">Main</string>
     <string name="tab_subscriptions">Subscriptions</string>
-    <string name="tab_bookmarks">Bookmarks</string>
+    <string name="tab_bookmarks">Bookmarked Playlists</string>
     <string name="tab_new">New Tab</string>
     <string name="tab_choose">Choose Tab</string>