am 5020a873: Merge "cherrypick from jb-mr2-docs docs: Training class for game controllers. Change-Id: I697770aee8604c965c3730691459c1e8f10705da" into klp-docs

* commit '5020a8736f3319d295d31bed421f837788878451':
  cherrypick from jb-mr2-docs docs: Training class for game controllers. Change-Id: I697770aee8604c965c3730691459c1e8f10705da