[Autofill] Fix test PrefillFormAndFill for flag AutofillSkipPreFilledFields

Disables the feature flag `features::kAutofillSkipPreFilledField` in
test `AutofillInteractiveTest.PrefillFormAndFill` to specifically test
Autofill's ability to overwrite pre-filled fields.

Bug: 1523213,1496673
Change-Id: I6cf238cd8ec54e0476fcd654e2255def7bf89615
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5249311
Reviewed-by: Jihad Hanna <jihadghanna@google.com>
Reviewed-by: Matthias Körber <koerber@google.com>
Commit-Queue: Wolfgang Billenstein <bwolfgang@google.com>
Cr-Commit-Position: refs/heads/main@{#1256156}