If we attempt to it will abort (because virtmgr will abort), and
service manager will keep trying to sstart it forever.
To avoid having a third copy of the hypervisor properties code,
extract it to a library.
Fix "vm info" so it works even in the absence of VM support, by not
connecting to virtmgr when we don't need to.
Also remove duplication from the composd_cmd build file, to make it
harder to accidentally break the test build.
Bug: 254599807
Test: "vm info", "vm list", "composd test-compile" with & without
VM enabled
Test: atest composd_cmd.test
Change-Id: I1f33e231fcf9c77ce16a6b2cfb51d67da3986a6d
Alan Stokes