Merge pull request #18524 from unoplatform/dev/spouliot/hrm-def-ctor-fix

fix: Ensure HttpRequestMessage.Headers are assigned when default ctor is used

src/Uno.UWP/Web/Http/HttpRequestMessage.cs

@@ -13,9 +13,8 @@ public HttpRequestMessage(HttpMethod method, Uri uri)
 		Headers = new HttpRequestHeaderCollection(this);
 	}
 
-	public HttpRequestMessage()
+	public HttpRequestMessage() : this(HttpMethod.Get, null)
 	{
-		Method = new HttpMethod("GET");
 	}
 
 	public Uri RequestUri { get; set; }