Added --args to cros_run_vm_test.

This --args is passed directly to run_remote_tests.sh.

BUG=none
TEST=./cros_run_vm_test --args=... ... works for args with spaces.

Change-Id: I2caac0a51fccd97983faf3a7a38eb56ee7753057
Reviewed-on: https://gerrit.chromium.org/gerrit/31282
Reviewed-by: Nirnimesh <nirnimesh@chromium.org>
Commit-Ready: asharif <asharif@chromium.org>
Tested-by: asharif <asharif@chromium.org>