fate/cbs: update the two film grain cbs_av1 tests

They were missed in the previous commit.

Signed-off-by: James Almer <jamrial@gmail.com>

tests/ref/fate/cbs-av1-av1-1-b10-23-film_grain-50

@@ -1 +1 @@
-5fe6622ac6cb22dd10dfbe9e70e82d4e
+aaddbf87bdf9b5ac4b1ab4fe802c410b

tests/ref/fate/cbs-av1-av1-1-b8-23-film_grain-50

@@ -1 +1 @@
-93e578da4b2bdb70ce0a92262da930ec
+2556d6d30469c647c6262130d8eb0531