debian: remove old usage jars during upgrade (#2552)

This removes old cloudstack-usage jars during upgrade as part of
the pre-install step of cloudstack-usage deb package.

This fixes #2542.

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: yadvr

debian/cloudstack-usage.preinst

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+set -e
+
+if [ "$1" = upgrade ]; then
+    # Remove old usage jars
+    rm -f /usr/share/cloudstack-usage/lib/*.jar
+fi