Update tests for HttpURLConnection.disconnect() changes

These changes are associated with external/mockwebserver
and external/okhttp commits.

URLConnectionTest#testDisconnectedConnection
 - Affected by the bug fix.

URLConnectionTest#testSslFallback
  - Affected by changes to MockWebServer. Handshake failures
    are no longer queued/recorded.

HttpsURLConnectionTest
  - API changes related to MockWebServer.

Bug: 18083851
Change-Id: Iec211a1e1e713623ccc8f8ca1de79833abe2f961