Replace interal okhttp APIs

Connectivity is becoming a mainline module in S but mainline
modules are not allowed to use non-formal APIs. Thus, replace
internal okhttp APIs to stable libcore APIs which are created for
using HttpURLConnectionFactory.

Bug: 182238821
Test: atest FrameworksNetTests
Change-Id: I56ba1b9e6e94f9c6519c3f1c8f0c5993fccbe185
1 file changed
tree: d1a2fa4bcd0b470cb10aa9192b02d601cf10367f
  1. core/
  2. framework/
  3. service/
  4. services/
  5. tests/
  6. OWNERS