(Re)Introduce "enabled by admin" UI state

(Re)Introduce "enabled by admin" / "disabled by admin" SettingsUI state.

ag/18665634 changed behavior: When enterprise policy restricts the
user's ability to change the "auto time" and "auto time zone" toggle,
the toggle was hidden rather than "visible but disabled".

Bug 266693620 demonstrates testers are checking for the behavior.

This commit returns the old behavior for the "auto time" and "auto time
zone" SettingUI behavior, i.e. the user can see the toggle and its
setting value, but is told that it is under admin control and the
current setting value.

See the bug for more info / historic behavior analysis.

Bug: 266693620
Test: Manual testing with TestDPC
Test: atest to confirm existing tests do not fail
Change-Id: I0a605054312547fbd44fc34025ee36b075e05e01