OpenJDK 11: Merging in java.net.URLEncoder and URLDecoder

This is part of merging upstream changes from OpenJDK 11.0.13. This CL
merges URLEncoder and URLDecoder

There are 2 new APIs added:
    static String encode(String, Charset);
    static String decode(String, Charset);

Tests were added for all of the new APIs.

Test: m droid
Test: atest CtsLibcoreOjTestCases:test.java.net.URLEncoder.{TestName}
Test: atest CtsLibcoreOjTestCases:test.java.net.URLDecoder.{TestName}
Change-Id: Id6bd626d46e68716b8d5b7d27c2d34170e80f952
15 files changed