Avoid extracting the baggage from null values (#11396)

Avoid extracting the baggage from null values

Co-authored-by: devflow.devflow-routing-intake <devflow.devflow-routing-intake@kubernetes.us1.ddbuild.io>

Author: amarziali

dd-trace-core/src/main/java/datadog/trace/core/baggage/BaggagePropagator.java

@@ -209,7 +209,10 @@ private Baggage parseBaggageHeaders(String input) {
     }
 
     @Override
-    public void accept(String key, String value) {
+    public void accept(String key, @Nullable String value) {
+      if (value == null) {
+        return;
+      }
       // Only process tags that are relevant to baggage
       if (BAGGAGE_KEY.equalsIgnoreCase(key)) {
         Baggage parsed = parseBaggageHeaders(value);