enable to work on android 2.2
Use the peer's settings for outgoing window updates.

(cherry picked from commit 818d17e3650f5c0fa048ae52279c559cd255f738)
Merge pull request #622 from takke/okhttp_15_fix_for_android2_2

enable to work on android 2.2
Start change log.
Merge branch 'okhttp_15' of https://github.com/square/okhttp into okhttp_15