Fix HttpsUrlConnection#setDefaultHostnameVerifier.

okhttp uses an internal verifier (an updated version of
DefaultHostnameVerifier) unless a verifier is set on the
client.

Fixes URLConnectionTest#testHttpsWithCustomTrustManager

(cherry picked from 631989e8)

bug: 10211309

Change-Id: I281e1b00382c1c9ccb160f34d5fb79c763c05b70