Reapply an upstream OkHttp change to Android for HttpUrl

Manually reapplied change from upstream to address HttpUrl encoding issues.

Upstream details:
Comment:
Don't percent-encode non-ASCII characters in fragments

Fixes https://github.com/square/okhttp/issues/1635
SHA: f4feb0adfcd8e209f90d4fffb6facf5c07f57110

Bug: 27590872
Change-Id: I827536ced778254103bdbe9d4b54baa4a889c058