Update PropertiesSheetListener.java

[njain2208]

PR Overview:

---

This PR fixes the flaky/non-deterministic behavior of the following test because it assumes the ordering.

org.drools.decisiontable.parser.RuleWorksheetParseFromFileTest#testWorkbookParse

org.drools.decisiontable.parser.RuleWorksheetParse2Test#packageLevelAttributesShouldNotBeDuplicated

Test Overview:

---

In the above tests, the tests make an internal call to the PropertiesSheetListener.java. PropertiesSheetListener file has _rowProperties map that has been initialized as HashMap which is flaky in nature. This causes the above tests to fail.

This flakiness was identified by the nondex tool created by the researchers of UIUC.

[ERROR]   RuleWorksheetParse2Test.packageLevelAttributesShouldNotBeDuplicated:165 
Expecting throwable message:
  "Multiple values for AGENDA-GROUP in cells [C4, C3]"
to contain:
  "C3, C4"
but did not.

[ERROR] Failures: 
[ERROR]   RuleWorksheetParseFromFileTest.testWorkbookParse:98 
Actual and expected have the same elements but not in the same order, at index 0 actual element was:
  "lah.di.dah"
whereas expected element was:
  "blah.class1"

You can reproduce the issue by running the following commands (you can reproduce the error for other tests by changing the test):

mvn install -pl  drools-decisiontables  -am -DskipTests
mvn test -pl drools-decisiontables  -Dtest=org.drools.decisiontable.parser.RuleWorksheetParseFromFileTest#testWorkbookParse
mvn -pl drools-decisiontables edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.drools.decisiontable.parser.RuleWorksheetParseFromFileTest#testWorkbookParse

Fix:

---

To fix the issue I have changed the HashSet with LinkedHashSet which is deterministic in nature.

https://github.com/njain2208/incubator-kie-drools/blob/9b243b3fa1b290117441675118409f99b46d0e8b/drools-decisiontables/src/main/java/org/drools/decisiontable/parser/xls/PropertiesSheetListener.java#L44

[tkobayas]

Thank you!