Merge: Strip content length in requests with "transparent" gzip handling

Original AOSP/libcore commit from Brian Carlstrom:
We need to strip both the Content-Length and the Content-Encoding
for such requests. In such requests, it will be the length of the
compressed response. We hide the fact that compression is taking place
from clients, so we shouldn't give them the content length either.

Change-Id: I80713ab33143945c5e2656f478d83cc9e60226a8
Merge pull request #99 from square/jwilson/transparentgzip

Merge: Strip content length in requests with "transparent" gzip handling