Charset of response must be geted from response.getEntity() instead of the ByteArrayEntity that is build in setEntity method (#948)

(cherry picked from commit cfd886a)

Author: iroqueta

java/src/main/java/com/genexus/internet/HttpClientJavaLib.java

@@ -728,7 +728,7 @@ public String getString() {
 			return "";
 		try {
 			this.setEntity();
-			Charset charset = ContentType.getOrDefault(entity).getCharset();
+			Charset charset = ContentType.getOrDefault(response.getEntity()).getCharset();
 			String res = EntityUtils.toString(entity, charset);
 			if (res.matches(".*[Ã-ÿ].*")) {
 				res = EntityUtils.toString(entity, StandardCharsets.UTF_8);