am 2cd90733: am 7bf1c661: am 034d89d9: docs: cherrypick Change-Id: I3d871d494cf1f626df701efaa43058b66893259e docs: add info about customizing the density of an AVD from command line; and a few editorial things like fix the TOCs

* commit '2cd90733cc17dcebb682d82f9dcf847877627043':
  docs: cherrypick Change-Id: I3d871d494cf1f626df701efaa43058b66893259e docs: add info about customizing the density of an AVD from command line; and a few editorial things like fix the TOCs