user_profile_data_file is mlstrustedobject. And it needs to be,
because we want untrusted apps to be able to write to their profile
files, but they do not have levels.
But now we want to apply levels in the parent directories that have
the same label, and we want them to work so they need to not be
MLS-exempt. To resolve that we introduce a new label,
user_profile_root_file, which is applied to those directories (but no
files). We grant mostly the same access to the new label as
directories with the existing label.
Apart from appdomain, almost every domain which accesses
user_profile_data_file, and now user_profile_root_file, is already
mlstrustedsubject and so can't be affected by this change. The
exception is postinstall_dexopt which we now make mlstrustedobject.
Bug: 141677108
Bug: 175311045
Test: Manual: flash with wipe
Test: Manual: flash on top of older version
Test: Manual: install & uninstall apps
Test: Manual: create & remove user
Test: Presubmits.
Change-Id: I4e0def3d513b129d6c292f7edb076db341b4a2b3
7aa40413ae