Charset can be used directly. (#10431)

Author: AlexeyKuznetsov-DD

dd-java-agent/appsec/src/main/java/com/datadog/appsec/util/AppSecVersion.java

@@ -1,5 +1,7 @@
 package com.datadog.appsec.util;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import datadog.environment.SystemProperties;
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
@@ -18,7 +20,7 @@ public class AppSecVersion {
     try (final BufferedReader br =
         new BufferedReader(
             new InputStreamReader(
-                AppSecVersion.class.getResourceAsStream("/appsec.version"), "UTF-8"))) {
+                AppSecVersion.class.getResourceAsStream("/appsec.version"), UTF_8))) {
       final StringBuilder sb = new StringBuilder();
 
       for (int c = br.read(); c != -1; c = br.read()) {

dd-trace-api/src/main/java/datadog/trace/api/DDTraceApiInfo.java

@@ -1,5 +1,7 @@
 package datadog.trace.api;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
 
@@ -11,7 +13,7 @@ public class DDTraceApiInfo {
     try (final BufferedReader br =
         new BufferedReader(
             new InputStreamReader(
-                DDTraceApiInfo.class.getResourceAsStream("/dd-trace-api.version"), "UTF-8"))) {
+                DDTraceApiInfo.class.getResourceAsStream("/dd-trace-api.version"), UTF_8))) {
       final StringBuilder sb = new StringBuilder();
 
       for (int c = br.read(); c != -1; c = br.read()) {

dd-trace-core/src/main/java/datadog/trace/core/DDTraceCoreInfo.java

@@ -1,5 +1,7 @@
 package datadog.trace.core;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import de.thetaphi.forbiddenapis.SuppressForbidden;
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
@@ -17,7 +19,7 @@ public class DDTraceCoreInfo {
     try (final BufferedReader br =
         new BufferedReader(
             new InputStreamReader(
-                DDTraceCoreInfo.class.getResourceAsStream("/dd-trace-core.version"), "UTF-8"))) {
+                DDTraceCoreInfo.class.getResourceAsStream("/dd-trace-core.version"), UTF_8))) {
       final StringBuilder sb = new StringBuilder();
 
       for (int c = br.read(); c != -1; c = br.read()) {