T4802: Fix up issues with apparmor-dbus testing

Fix up issues found during testing in more a representative environment, I'd originally managed to test in the wrong environment and not fully understood how the test was to be run...

• Use journal, not audit log. This also requires different parsing.
• Binaries will be in subdirectores.
• Use available commands to simplify script
• Fail if test fails, don't continue.
• A few syntax cleanups