Refactor and improve LegacyFileAccessTest

Make LegacyFileAccessTest use utilities from TestUtils to reference
default directories.
Don't use File variable to reference more than one file in a case.
Ensure default top-level directories are created before running the
test.

Test: atest FuseDaemonHostTest:LegacyAccessHostTest
Test: un@Ignore ignored test case and make sure we get the same errors
Bug: 10873947

Change-Id: I25925f9bb05074249a2fde6561c0ef47eaf50eb8
2 files changed