am a2739fa7: am a4c5bba0: add document about GoogleApiClient and one about GoogleAuthUtil also remove the Authorization document from the Google Services section. bug:10679818

* commit 'a2739fa795981f597b044e93a5c552051cfe1c00':
  add document about GoogleApiClient and one about GoogleAuthUtil also remove the Authorization document from the Google Services section. bug:10679818