[roll] Roll fuchsia [setui] Make DeviceStorage a singleton

DeviceStorage is now a singleton that manages requests
for all types, rather than getting a single DeviceStorage
for each type of storage that's being accessed. This also
removes the needed for a large amount of Mutex types
throughout setui.

DeviceStorageFactory is also modified to return that
singleton rather than return a new instance for each
request for storage. The switch to internal mutability
for DeviceStorage also requires the addition of an
initialization done by DeviceStorageFactory. That
initialization requires heavy modification of
InMemoryStorageFactory, including a new method
to store data without update the cache within
DeviceStorage, mimicking the condition where data
is stored on disk before it's accessed by DeviceStorage.

Original-Bug: 67371
Tests: fx test -o setui_service_tests
Manually ran through device settings and rebooted device to
ensure storage was persisted.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/486439
Original-Revision: 5772278bf754dadcc0eb103a6e84bdd3e3dd1e15
GitOrigin-RevId: b88711b436b6e549fb60dab981a97ba5fa7b27a6
Change-Id: I2684cca50a66a60c245f6eafe88fb42883e34493