Pull latest OkHttp code from upstream

okio:

okio is now managed upstream as a separate project but has
been included here as a sub directory: the okio version here
is intended only for use with OkHttp.
okio is synced to upstream commit
82358df7f09e18aa42348836c614212085bbf045.
See okio/README.android for local changed needed to make it
compile.

okhttp:

This is effectively an upgrade from a snapshot close to
OkHttp 1.5 with Android additions to a snapshot close to
OkHttp 2.2.
okhttp was synced to upstream commit
0a197466608681593cc9be9487965a0b1d5c244c
See README.android for local changes needed to make it
compile.

Most of the old Android changes have been pushed upstream
and other upstream changes have been made to keep OkHttp
working on Android.

TLS fallback changes have not been upstreamed yet:
bcce0a3d
ede2bf1a

This means that some CTS tests will start to fail. A later
commit will fix those changes when it has been accepted
upstream.

There are associated changes in libcore and frameworks/base.

Change-Id: I0a68b27b1ec7067be452671bc591edfd84e310f2