[CCSG] Replace deprecated AutofillClock::Now() to base::Time::Now()

AutofillClock::Now() is deprecated and is replaced by base::Time::Now().

Low-Coverage-Reason: TESTS_IN_SEPARATE_CL
Bug: 409962888
Change-Id: Ieadaf4630adcc545959b3113194de9938e35ef91
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6990431
Commit-Queue: Jihad Hanna <jihadghanna@google.com>
Reviewed-by: Jihad Hanna <jihadghanna@google.com>
Auto-Submit: Mikita Kuchyn <kuchyn@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1522373}