crash-service: Permit service & app livedump API clients

crash-service: Permit service & app livedump API clients

The d-bus livedump_pid API can be used by both services and apps.

For service to use the API it should be member of (supplementary)
priv_livecoredumper group.

For application to use the API it should be given the
"http://tizen.org/privilege/internal/livecoredump" privilege.
However, it's internal privilege so it can't be given from the
application manifest. See 'livedumper' section in NOTES file
for hints.

Change-Id: I01586c2c00f7a15d2553e4284ce373a03f9433b1