Fix sonar issues in drools-applications

Fix sonar issues in drools-applications

Addressed sonar issue, "Move constants to a class or enum.", by
moving the "manager" object from the ControlLoopMetrics interface
into a utility class, ControlLoopMetricsManager.
Addressed sonar issue, "duplicated blocks of code must be removed.",
by refactoring PolicyGuardYamlToXacml, extracing common functions.
Addressed sonar issue, "Remove this unused import", in
RestControlLoopManager.
Addressed sonar issue, "Refactor this method to throw at most one
checked exception", in event manager.
Fixed likely new sonar issue with assigning to a parameter.
Moved logging line to more appropriate place.
Addressed reviewer comment:
  Use "replace" instead of "replaceAll", thus avoiding escaping

Change-Id: I47db957c83c1b3e2bd2330474e261987c6f0aac6
Issue-ID: POLICY-1967
Signed-off-by: Jim Hahn <jrh3@att.com>