Turn down yum install-packages

When debugging, this is very noisy for very little value.  If we need
to specifically debug this script we can turn up the level.

Change-Id: Ie15f16397c37e718aa919853697cbf2c5c08503c

elements/yum/bin/install-packages

@@ -14,7 +14,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-if [ ${DIB_DEBUG_TRACE:-0} -gt 0 ]; then
+if [ ${DIB_DEBUG_TRACE:-0} -gt 1 ]; then
     set -x
 fi
 set -eu