Apply upstream OkHttp HttpUrl fix

Upstream information:
Comment:
Encode enough to make URI happy.

Plus a bunch of test cases around this unfortunate case.

Closes https://github.com/square/okhttp/issues/1872
SHA: 080e7536ab8c2d07db58628f75a4140012e2a581

Bug: 27590872
Change-Id: I55670bdc97ffe162876b5ec93a150823a0549a40