Provide RSA2048 as per RFC

Original CL here:
https://codereview.webrtc.org/1329493005

That CL is in patch set #1 of this CL.
This CL resolves a method collision in Chrome.

BUG=webrtc:4972

Review URL: https://codereview.webrtc.org/1394223002

Cr-Original-Commit-Position: refs/heads/master@{#10222}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 4e572470a3f181a043f9f9b98cc0153b7195b9f5
6 files changed