Remove deprecated charset handling in JniHelper

Chromium->Webrtc roll is blocked due to compile error here.

Bug: none
Change-Id: Ibe76b7480309841ffee0efe2bc85de453c6b7ee9
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/455201
Commit-Queue: Zoé Lepaul <zlep@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Zoé Lepaul <zlep@webrtc.org>
Auto-Submit: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47088}

sdk/android/src/java/org/webrtc/JniHelper.java

diff --git a/sdk/android/src/java/org/webrtc/JniHelper.java b/sdk/android/src/java/org/webrtc/JniHelper.java
index 0d56d5d..9cacd5f 100644
--- a/sdk/android/src/java/org/webrtc/JniHelper.java
+++ b/sdk/android/src/java/org/webrtc/JniHelper.java
@@ -11,6 +11,7 @@
 package org.webrtc;
 
 import java.io.UnsupportedEncodingException;
+import java.nio.charset.StandardCharsets;
 import java.util.Map;
 
 /**
@@ -21,11 +22,7 @@
   // TODO(bugs.webrtc.org/8632): Remove.
   @CalledByNative
   static byte[] getStringBytes(String s) {
-    try {
-      return s.getBytes("ISO-8859-1");
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException("ISO-8859-1 is unsupported");
-    }
+    return s.getBytes(StandardCharsets.ISO_8859_1);
   }
 
   // TODO(bugs.webrtc.org/8632): Remove.