Move ablation seed to local state

This CL moves the ablation seed from a profile preference to local
state. This way we guarantee that the behavior for a single UKM Client
ID is consistent.

Bug: 348362142
Change-Id: I6d8e08ae4529ad7dd95088e515dc0f2e46fbaa96
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5704059
Commit-Queue: Bruno Braga <[email protected]>
Reviewed-by: Tommy Martino <[email protected]>
Auto-Submit: Dominic Battré <[email protected]>
Code-Coverage: [email protected] <[email protected]>
Reviewed-by: Bruno Braga <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1328028}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 13c07ca..a9e8315 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -1561,6 +1561,7 @@
   accessibility::AccessibilityPrefsController::RegisterLocalStatePrefs(
       registry);
 #endif
+  autofill::prefs::RegisterLocalStatePrefs(registry);
   breadcrumbs::RegisterPrefs(registry);
   browser_shutdown::RegisterPrefs(registry);
   BrowserProcessImpl::RegisterPrefs(registry);