Add new Custom step for Self Promotion Condition to be included in the Declarative Pipeline.

The returning function name would probably be : "selfPromote"  which would take "job" and "buildNumber" as its input parameters.

Acceptance Criteria:

• a new class for selfPromote is made with right ParameterValues sent to SelfPromotion.java and the new PromotionProcess class.
• Compilation/Unit tests before Merge.