Merge "init: fix README.md about perform_apex_configs"

  _options_ include "barrier=1", "noauto\_da\_alloc", "discard", ... as

  a comma separated string, e.g. barrier=1,noauto\_da\_alloc

`parse_apex_configs`

> Parses config file(s) from the mounted APEXes. Intended to be used only once

  when apexd notifies the mount event by setting apexd.status to ready.

`perform_apex_config`

> Performs tasks after APEXes are mounted. For example, creates data directories

  for the mounted APEXes, parses config file(s) from them, and updates linker

  configurations. Intended to be used only once when apexd notifies the mount

  event by setting `apexd.status` to ready.

`restart <service>`

> Stops and restarts a running service, does nothing if the service is currently