Switch frameworks/base over from @hidden Charsets to public StandardCharsets.

Bug: 3484927
Change-Id: I5d136d2ee629588538602766a182ae14ce5fc63c
diff --git a/core/java/android/net/Uri.java b/core/java/android/net/Uri.java
index cc6903d..60c5000 100644
--- a/core/java/android/net/Uri.java
+++ b/core/java/android/net/Uri.java
@@ -25,7 +25,7 @@
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
-import java.nio.charset.Charsets;
+import java.nio.charset.StandardCharsets;
 import java.util.AbstractList;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -1688,7 +1688,7 @@
                     return "";
                 } else {
                     String encodedValue = query.substring(separator + 1, end);
-                    return UriCodec.decode(encodedValue, true, Charsets.UTF_8, false);
+                    return UriCodec.decode(encodedValue, true, StandardCharsets.UTF_8, false);
                 }
             }
 
@@ -1927,7 +1927,7 @@
         if (s == null) {
             return null;
         }
-        return UriCodec.decode(s, false, Charsets.UTF_8, false);
+        return UriCodec.decode(s, false, StandardCharsets.UTF_8, false);
     }
 
     /**