am 2ef3952d: cherrypick from jb-mr2-docs docs: Android training for Activity testing. Change-Id: I7167732c849d5a4a36c808cc852ddfcdc8e60bd7

* commit '2ef3952d8e62b71baca176b3e17315a37facd34a':
  cherrypick from jb-mr2-docs docs: Android training for Activity testing. Change-Id: I7167732c849d5a4a36c808cc852ddfcdc8e60bd7