download-toolchain-sources.sh: Use android.googlesource.com

This patch updates all files to refer to the new location of the
AOSP source server, which is now android.googlesource.com.

It updates the download-toolchain-sources.sh script to download
from this server, using the https:// git protocol, instead of
git://

+ Remove the --git-http option since it isn't supported by
  the new servers, nor really desirable since the https://
  protocol should work across firewalls.

  In case you need an alternative, you can still use the
  --git-base option, so nothing of value was lost here.

Change-Id: I99816a4791741474708ad390f96e2ba18cea35b8
7 files changed