Increase size limit for http requests sent to API server.

Currently, the limit is 100k. If the post request is larger than this, API server will throw exception.
Increased it to 1M till a more permanent solution is implemented.

Change-Id: Ia7e9150b274fff4b03a4c12ab63c444d25e78187
Closes-Bug: 1394374
(cherry picked from commit ff37fdfad4ba8c30c7207db5f1f717eedd906058)