Include SDK sandbox while calculating app and user size

SDK sandbox storage has been separated and need to be specially included
while getting app size and user size.

While calculating app size manually, each of the subdirectories in the
sdk sandbox storage (shared, directories for each sdk etc.) are added up
separately to the total. This is because each of these subdirectories
would contain a cache storage that needs to be added to the cache
calculation.

Quota calculation for sandbox storage is already present.

Bug: 215506889
Test: atest SdkSandboxStorageHostTest#testSdkDataIsAttributedToApp
Ignore-AOSP-First: Will cherry pick to AOSP once dependent CLs are also
cherry-picked.

Change-Id: I94bc30f7e47e06b3b60d28f16a647a2a0daaae93
(cherry picked from commit 08c0ff36)