Fix flaky test for TestAzureLogAnalyticsProvenanceReportingTask.testAddField2 in dir nifi-nar-bundles/nifi-azure-bundle/nifi-azure-reporting-task by LinkedHashMap

[Stranger3333]

The problem occurs at the method TestAzureLogAnalyticsProvenanceReportingTask.testAddField2, which compares two Jsonobject after calling toString() method. One Jsonobject is expectedJson, which is generated by a hardcoded String expectedjsonString with a fixed sequence of JSON fields. Another Jsonobject is actualJson, which by passing HashMap as a parameter to the method AzureLogAnalyticsProvenanceReportingTask.addField. This method will add entries of the map to the JsonObjectBuilder builder, then actualJson is generated by calling builder.build().

The flaky test exists since the HashMap is non-deterministic or unordered, so the sequence of adding entries to builder is non-deterministic. Thus, assertEquals(expectedJson.toString(), actualJson.toString()); could result some tests fail.
The solution is changing HashMap to LinkedHashMap, an ordered map, and then adding entries by order.

This PR uses LinkedHashMap to make the testAddField2 deterministic.

The reason that it may be accepted by open-source developers is that I only changed a couple of lines in the test method, without changing any main code. The functioning of the whole project will work as before. Also, I only imported the LinkedHashMap from java.util package, which will not affect the security of the codebase from my view.