Migrate dd-trace-core groovy files to java part 9

we migrate 20 tests from the propagation package:
 - TagKeyTest
 - TagValueTest
 - B3HttpExtractorTest
 - B3HttpInjectorPaddedTest
 - B3HttpInjectorTest
 - DatadogHttpExtractorTest
 - DatadogHttpInjectorTest
 - DatadogPropagationTagsTest
 - HaystackHttpExtractorTest
 - HaystackHttpInjectorTest
 - HttpExtractorTest
 - HttpInjectorB3PaddingTest
 - HttpInjectorTest
 - NoneHttpExtractorTest
 - TracingPropagatorTest
 - W3CHttpExtractorTest
 - W3CHttpInjectorTest
 - W3CPropagationTagsTest
 - XRayHttpExtractorTest
 - XRayHttpInjectorTest

Author: jpbempel

dd-trace-core/src/main/java/datadog/trace/core/propagation/B3HttpCodec.java

@@ -29,9 +29,9 @@ class B3HttpCodec {
   private static final String B3_SPAN_ID = "b3.spanid";
   static final String TRACE_ID_KEY = "X-B3-TraceId";
   static final String SPAN_ID_KEY = "X-B3-SpanId";
-  private static final String SAMPLING_PRIORITY_KEY = "X-B3-Sampled";
+  static final String SAMPLING_PRIORITY_KEY = "X-B3-Sampled";
   // See https://github.com/openzipkin/b3-propagation#single-header for b3 header documentation
-  private static final String B3_KEY = "b3";
+  static final String B3_KEY = "b3";
   private static final String SAMPLING_PRIORITY_ACCEPT = String.valueOf(1);
   private static final String SAMPLING_PRIORITY_DROP = String.valueOf(0);
 

dd-trace-core/src/main/java/datadog/trace/core/propagation/HaystackHttpCodec.java

@@ -29,17 +29,17 @@ class HaystackHttpCodec {
   private static final Logger log = LoggerFactory.getLogger(HaystackHttpCodec.class);
 
   // https://github.com/ExpediaDotCom/haystack-client-java/blob/master/core/src/main/java/com/expedia/www/haystack/client/propagation/DefaultKeyConvention.java
-  private static final String OT_BAGGAGE_PREFIX = "Baggage-";
-  private static final String TRACE_ID_KEY = "Trace-ID";
-  private static final String SPAN_ID_KEY = "Span-ID";
+  static final String OT_BAGGAGE_PREFIX = "Baggage-";
+  static final String TRACE_ID_KEY = "Trace-ID";
+  static final String SPAN_ID_KEY = "Span-ID";
   private static final String PARENT_ID_KEY = "Parent-ID";
 
-  private static final String DD_TRACE_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Trace-Id";
-  private static final String DD_SPAN_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Span-Id";
-  private static final String DD_PARENT_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Parent-Id";
+  static final String DD_TRACE_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Trace-Id";
+  static final String DD_SPAN_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Span-Id";
+  static final String DD_PARENT_ID_BAGGAGE_KEY = OT_BAGGAGE_PREFIX + "Datadog-Parent-Id";
 
-  private static final String HAYSTACK_TRACE_ID_BAGGAGE_KEY = "Haystack-Trace-ID";
-  private static final String HAYSTACK_SPAN_ID_BAGGAGE_KEY = "Haystack-Span-ID";
+  static final String HAYSTACK_TRACE_ID_BAGGAGE_KEY = "Haystack-Trace-ID";
+  static final String HAYSTACK_SPAN_ID_BAGGAGE_KEY = "Haystack-Span-ID";
   private static final String HAYSTACK_PARENT_ID_BAGGAGE_KEY = "Haystack-Parent-ID";
 
   // public static final long DATADOG = new BigInteger("Datadog!".getBytes()).longValue();