Rename NewTimeServiceHelper: it is no longer new

The original TimeServiceHelper / TimeServiceHelperImpl were deleted in
commit a4011139.  This commit also changes log messages/tests to
correct remaining references to NewNitzStateMachineImpl.

Bug: 149014708
Test: build only
Merged-In: I35854e853ded5be9ba129a970279e8ef122e2eb2
Change-Id: I35854e853ded5be9ba129a970279e8ef122e2eb2
(cherry picked from commit 46ed5cdc)