Track moving of OkHttp facade API to new package.

Track moving of OkHttp facade API to new package.

Another CL in this topic moves the classes from
  libcore.net.http
to
  com.squareup.okhttp.internalandroidapi.
In jarjar'ed build targets, this becomes
  com.android.okhttp.internalandroidapi.

This facade constitutes the API via which non-libcore parts
of the Android platform (currently framework) may access
OkHttp. It's moving because libcore.net.http is already
part of libcore, and the overlap of packages is problematic
for builds with EXPERIMENTAL_USE_OPENJDK9 set to true.

Bug: 68220880
Test: Treehugger
Change-Id: Ia79966563cc0b5ab0923d54c21e54b6192d8c990
Exempt-From-Owner-Approval: Jeff Sharkey is an owner, but only one of his accounts is listed as an owner (@android.com vs. @google.com)