Update based on latest master configuration.
Changes:
- switch to kirkstone
- add required usrmerge feature to kas-security-alt configuration
- add whitespaces around assignement
- add common dldir/sstate
- don't build apparmor in musl configs
- only enable ptest for the test image
- Update the kas configuration file versions to 19 to match kas 4.8.x.
- Change refspec to branch to remove deprecation warnings.
- Add quoting around URLs to match upstream examples.
Signed-off-by: Scott Murray <scott.murray@konsulko.com>