Fix sonar issues in drools-pdp

Fix sonar issues in drools-pdp

Address sonar issue, "Move constants to a class or enum", by
moving them from interfaces to classes:
  ActiveStandbyFeatureApi
  StateManagementFeatureApi
  PolicyResourceLockFeatureApi
  PolicySessionFeatureApi
  DroolsController
  DroolsControllerFeatureApi
  PolicyControllerFeatureApi
  PolicyEngineFeatureApi
  HealthCheck
  SystemPersistence
  EventProtocolCoder
  PolicyController
  PolicyEngine
  TestTransaction
  MdcTransaction
Address sonar issue, "Move constants to a class or enum", by
change the interface to a class:
  DroolsProperties
Address sonar issue, "Override the "equals" method in this class", by
adding equals & hashCode to:
  DroolsPdpEntity
  DroolsPdpImpl
Use lombok for a number of getters & setters.
Address sonar issue, "Define a constant instead of duplicating this
literal" in:
  DroolsPdpsElectionHandler
  JpaDroolsPdpsConnector
  MavenDroolsController
  GenericEventProtocolCoder
  GsonProtocolCoderToolset
  RestManager
Address sonar issue, "Remove the parentheses around the parameter" in:
  MavenDroolsController
Address sonar issue, "Replace this lambda with a method reference" in:
  LifecycleFsm
Address sonar issue, "Move this constructor to comply with Java Code
Conventions" in:
  LifecycleStateRunning
Address sonar issue, "Replace this 'switch' statement by 'if'
statements to increase readability", as specified in:
  PolicyEngineManager
Address sonar issue, "Rename field to prevent any misunderstanding/clash
with field" in:
  MdcTransactionImpl
Address sonar issue, "Either log or rethrow this exception", in:
  RestManager
Address sonar issue, "Rename this constant name to" uppercase, by
replacing enums with static lists in:
  RestManager
Addressed review comments:
  Fixed license dates.
  Renamed getSiteName/setSiteName methods to getSite/setSite in
  the interface to match the field names in the implementation
  classes.
  Renamed *Instance classes to *Constants.
  Next round of review comments.

Change-Id: I1c26af9f194833dd773f2b25dc5f60cde163201c
Issue-ID: POLICY-1968
Signed-off-by: Jim Hahn <jrh3@att.com>