Add the root of crates by Context.getCrateDir

Context.getCrateDir() creates and returns the File for the
root of the crates for the application context. Any child directories
under the crates root in Context.getDataFile() is called
the crate directory.

For example:
  /data/user/0/com.exmaple.app/crates/IAmCratedFolder/decentFiles
  /data/user/0/com.exmaple.app/crates/IAmCratedFolder/decentDirs

Context.getCrateDir return the crate dir
  --> /data/user/0/com.exmaple.app/crates/IAmCratedFolder

The crate dir
  --> IAmCratedFolder
The decent directories or files are not crated folders
  --> decentFiles, decentDirs

Test: atest CtsOsTestCases:android.os.storage.cts.StorageCrateTest
Bug: 141660526
Change-Id: If3ec1e121fb8f72bab5571d6190378e3ae208832