Relax tests around HTTP header validation

An associated change in OkHttp is relaxing the validation to
make it closer to the behavior in M. This may be temporary and
could be removed in a future release of Android.

Bug: 28867041
(cherry picked from commit e62b4c5890b48404714004e3d8a167479222b87b)

Change-Id: I8e2e58a583979611d78f9de6e24bd3c5a7dc2879
1 file changed