Remove ~1/3 of the installd calls at boot.

When preparing CE storage for an app, we always perform a second call
to extract any newly created CE directory inode.  Let's simplify this
and just return the inode number from the createAppData() call.

Test: builds, boots, reads CE inodes after wipe
Bug: 33463450
Change-Id: I9b73da576800b56d7d0961dd4deb0b6a546acbe7