Typically installd will create cache directories for an app, and
store those inode numbers in the parent directory. However, when an
app deletes and recreates a cache directory, the (now invalid) inode
number is left floating around, and we could end up pointing at a
useful non-cache directory.
Fix this by updating the xattr when we create the cache directory
out in userspace.
Test: builds, boots
Bug: 34185870
Change-Id: I71526dd73230c938aceabd2c0a8e89d44cc1f169
83aacdee40