am 40afb97c: cherrypick Change-Id: I51ac719e414ac2794ff446d992bb946acb0fa896 docs: add button builder for android market apps

* commit '40afb97c3289cd3daae9a31f4829d660ba747d37':
  cherrypick Change-Id: I51ac719e414ac2794ff446d992bb946acb0fa896 docs: add button builder for android market apps