Replace usages of goog.now with Date.now in tests in preparation for removing `goog.now`. Note that as of cl/330763899 `goog.now` just calls `Date.now`, so that this change should generally be a noop. RELNOTES:n/a
Replace usages of goog.now with Date.now in tests in preparation for removing `goog.now`. Note that as of cl/330763899 `goog.now` just calls `Date.now`, so that this change should generally be a noop.
RELNOTES:n/a

PiperOrigin-RevId: 438912870
Change-Id: I69bc270cb3ddd953ddf975d252072b7e780b3087

google/closure-library,google/closure-library,google/closure-library,google/closure-library,google/closure-library