Merge "Update init documentation to reflect fs_config changes"

user <username>

  Change to username before exec'ing this service.

  Currently defaults to root.  (??? probably should default to nobody)

  Currently, if your process requires linux capabilities then you cannot use

  this command. You must instead request the capabilities in-process while

  still root, and then drop to your desired uid.

  As of Android M, processes should use this option even if they

  require linux capabilities.  Previously, to acquire linux

  capabilities, a process would need to run as root, request the

  capabilities, then drop to its desired uid.  There is a new

  mechanism through fs_config that allows device manufacturers to add

  linux capabilities to specific binaries on a file system that should

  be used instead. This mechanism is described on

  http://source.android.com/devices/tech/config/filesystem.html.  When

  using this new mechanism, processes can use the user option to

  select their desired uid without ever running as root.

group <groupname> [ <groupname> ]*

  Change to groupname before exec'ing this service.  Additional