Create misc_ce and misc_de directories on /mnt/expand

We want to store sdk data on the same volume as app data. Since sdk data
is stored in misc_ce and misc_de directory, we need to ensure they exist
on adopted storage mounted at /mnt/expand/<volume-uuid>.

This CL creates `/mnt/expand/<volume-uuid>/misc_{ce,de}` directories
when disk is mouted and then when user storage is prepared, the sdk root
directory is created.

By having these directories, we can now move the sdk data to other
volume when app data is moved.

Bug: b/222034645
Test: atest SdkSandboxStorageHostTest (see ag/17120883)
Ignore-AOSP-First: End to end test added which exists in internal branch
    only. Will cherry-pick this CL to aosp standalone once it is safely
    merged to internal branch.
Change-Id: I0e73d9ce105abec4b77c378cde58aa7365258f01