Added --skip option to skip services.

This option will be used by dumpstate so critical services (like meminfo
and cpuinfo) can be dumped earlier on and then skipped later (when the
rest of the services are dumped).

BUG: 26639621
Change-Id: Ied61431c4d03d7d2eb010edd77872fb7e6bae3bd
1 file changed