NEXUS-7786: Fix for non-fatal NPE on boot

Changes:
* QZ lifecycle managed by JSR250
* Capability left but "demoted", putting scheduler in "stand-by" mode is still useful
Currently we shutdown JSR-250 centrally, so need to make sure we share the same lifecycle module across all bundles. When we switch to individual bundle lifecycle management in the next container update this can be removed.
Merge pull request #902 from sonatype/NEXUS-7786-non-fatal-npe-qz

NEXUS-7786: Fix for non-fatal NPE on boot