Move disk usage utilities to its own library

Disk usage calculation will happen in more places now, so move the
installd calculation utilities out to its own library that only gets
built for the target.

Change-Id: Idceb6bd663ca6ab3d38fa00e57ee74a25b784855
diff --git a/libs/diskusage/Android.mk b/libs/diskusage/Android.mk
new file mode 100644
index 0000000..d54f8ad
--- /dev/null
+++ b/libs/diskusage/Android.mk
@@ -0,0 +1,24 @@
+# Copyright (C) 2010 The Android Open Source Project
+#
+# Licensed 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.
+
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libdiskusage
+
+LOCAL_MODULE_TAGS := optional
+
+LOCAL_SRC_FILES := dirsize.c
+
+include $(BUILD_STATIC_LIBRARY)
\ No newline at end of file