[POLICY-12] clean policy-persistence mod warnings

[POLICY-12] clean policy-persistence mod warnings

Takes care of the following warnings:

--IntegrityAuditIntegrationTest.java

import org.junit.Ignore is never used

import org.openecomp.policy.common.im.AdministrativeStateException
is never used

import org.openecomp.policy.common.im.IntegrityMonitor
is never used

import org.openecomp.policy.common.im.StandbyStatusException
is never used

import org.openecomp.policy.drools.core.DroolsPDPIntegrityMonitor
is never used

import org.apache.commons.logging.Log is never used

import org.apache.commons.logging.LogFactory is never used

value of the field IntegrityAuditIntegrationTest.sleepTime is not used

--IntegrityMonitorProperties.java

import org.apache.commons.logging.Log is never used

import org.apache.commons.logging.LogFactory is never used

--StandbyStateManagementTest.java

import org.openecomp.policy.drools.system.PolicyEngine is never

--RepositoryAudit.java

import java.nio.file.FileVisitor is never used

import java.util.concurrent.Callable is never used

--PMStandbyStateChangeNotifier.java

import org.openecomp.policy.drools.controller.internal.MavenDroolsController
is never used

import org.openecomp.policy.drools.event.comm.TopicEndpoint
is never used

--DroolsSessionEntity.java

The serializable class DroolsSessionEntity does not declare a static final
serialVersionUID field of type long

--DroolsPdpObject.java

Comparable is a raw type. References to generic type Comparable<T> should be parameterized

Comparable is a raw type. References to generic type Comparable<T> should be parameterized

Type safety: The method compareTo(Object) belongs to the raw type Comparable.
References to generic type Comparable<T> should be parameterized

--DroolsPdpsElectionHandler.java

The value of the local variable lowestPriorityPdp is not used

Change-Id: Idd563d74c1d6521f7a3759c441f7fe0597011b67
Signed-off-by: Jorge Hernandez <jh1730@att.com>