phosphor-dbus-monitor: journal behavior

[wvervoorn]

When using PDM I am running into problems when I try to use the "journal" functionality.

I found two issues:

1. journal doesn't work if a "bool" property group is passed in. If I add two call backs to generate a journal entry and I pass a "bool" property group in one and a "uint64" in the other the "uint64" entry will be generated while the other is not.
2. A "uint64" journal entry will only be generated is I also have a "watch" included for a "uint64" property group. I noticed this as I had a watch for a "bool" property and wanted to pass in a "unint64" property group as a workaround for the first issue. This was working but only as long as there was a watch for the "unint64" as soon as I removed this the journal entry wasn't generated any longer.

Please note I also added error logging entries and those were werking without problem. So it seems to be a "journal" specific issue.