Decrease free space required for autotest

Not sure why autotest needs so much space, during a locally run bvt test,
the space used only increased by a few mb.

Changing the value to 700MB so rialto barely passes.

TEST=Rialto now repairs successfully
BUG=chrome-os-partner:45875

Change-Id: Ife2a6b005c2068108be3f3ee5ef8ece779241748
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/302732
Commit-Ready: Alexandru Stan <amstan@chromium.org>
Tested-by: Alexandru Stan <amstan@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
diff --git a/global_config.ini b/global_config.ini
index 906bb6a..4bddc63 100644
--- a/global_config.ini
+++ b/global_config.ini
@@ -112,7 +112,7 @@
 # Transfer RPC logs to a RPC logging server
 rpc_logserver: False
 # Minimum amount of disk space required for AutoTest in GB
-gb_diskspace_required: 1.0
+gb_diskspace_required: 0.7
 # Minmum number of i-nodes for stateful, in 1000 i-node units.
 kilo_inodes_required: 100
 # Minimum amount of disk space required for encrypted stateful partition in GB