adding implementation for azure apim

Author: TophrC-dd

internal-api/src/main/java/datadog/trace/api/gateway/InferredProxySpan.java

@@ -46,6 +46,7 @@ public class InferredProxySpan implements ImplicitContextKeyed {
     SUPPORTED_PROXIES = new HashMap<>();
     SUPPORTED_PROXIES.put("aws-apigateway", "aws.apigateway");
     SUPPORTED_PROXIES.put("aws-httpapi", "aws.httpapi");
+    SUPPORTED_PROXIES.put("azure-apim", "azure.apim");
   }
 
   private final Map<String, String> headers;

internal-api/src/test/java/datadog/trace/api/gateway/InferredProxySpanTests.java

@@ -236,7 +236,7 @@ void testSupportedProxySystems(String proxySystem, String expectedSpanName) {
   }
 
   static Stream<Arguments> supportedProxySystems() {
-    return Stream.of(of("aws-apigateway", "aws.apigateway"), of("aws-httpapi", "aws.httpapi"));
+    return Stream.of(of("aws-apigateway", "aws.apigateway"), of("aws-httpapi", "aws.httpapi"), of("azure-apim", "azure.apim"));
   }
 
   @Test