How to set bundle start-level in fabric environment ?

Issue

• In Fabric environment In Fuse 6.1.0, start-level of bundle isn't useful and has no impact. But this behaviour changes in Fuse 6.2.1
• In Fuse 6.1.0 on Fabric environment, bundle start-level used to be consistent(start-level=60), but in Fuse 6.2.1 start-level assigned to custom bundles is lower than system bundles, so mostly these bundles are in installed/resolved state.
• If we explicitly set start-level to 100 for custom bundle than bundle is in active state.