[remoting][FTL] Fix connection with non-gmail account

The ME2ME authenticator will make sure the signaling message comes from
a sender with an expected JID. Currently for non-gmail account that JID
will be a GAIA JID that is different than the user's actual email. This
works for XMPP connections but won't work for FTL since FTL always uses
the user's actual email for message routing.

This CL makes the authenticator always use the user's actual email when
connecting through FTL.

Bug: 964165
Change-Id: I424435888a81a095e944d02decb49d52cec57e36
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1618018
Commit-Queue: Yuwei Huang <yuweih@chromium.org>
Reviewed-by: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661056}
5 files changed