macos: Make launchd processes interactive

When (and only when) starting hyperkit from a crc daemon instance
started through launchd, we've seen unexpected kernel panics in the
guest: #2020

If crc daemon is run from a console, this does not happen. If hyperkit
is run directly from a launchd service, even using different (Debian)
kernels, and nothing crc related, the kernel panic is reproducible.
Newer/older hyperkit versions exhibit this behaviour as well.
These panics happen more or less frequently depending on the machine,
for me they were happening 80% of the time.

Starting the crc daemon launchd service as an interactive process avoids
this problem (but don't ask me why exactly :-/ )

This fixes #2020

pkg/os/launchd/launchd_darwin.go

@@ -36,6 +36,8 @@ const (
 			<false/>
 			<key>RunAtLoad</key>
 			<true/>
+			<key>ProcessType</key>
+			<string>Interactive</string>
 		</dict>
 	</plist>`
 )