docs: Fix broken link in Volley training am: 05dd9d2c29 am: 346114e346 am: c8c2abed0e
am: 46c1d5a5d2

* commit '46c1d5a5d2b4c1d6a680f7af5c3973486c1fef2c':
  docs: Fix broken link in Volley training

Change-Id: Ib5ae3925cca39db0145bb4c6e6eeb53488bfc316