Turn on update password UI on iOS by default

ios/chrome/browser/experimental_flags.mm

Index: ios/chrome/browser/experimental_flags.mm
diff --git a/ios/chrome/browser/experimental_flags.mm b/ios/chrome/browser/experimental_flags.mm
index df980e9f4110cc0e5199b18048df174976f44916..aac30b83dc1ce47860784b34e379ab1b19b6c236 100644
--- a/ios/chrome/browser/experimental_flags.mm
+++ b/ios/chrome/browser/experimental_flags.mm
@@ -27,7 +27,7 @@ NSString* const kEnableViewCopyPasswords = @"EnableViewCopyPasswords";
 NSString* const kHeuristicsForPasswordGeneration =
     @"HeuristicsForPasswordGeneration";
 NSString* const kEnableReadingList = @"EnableReadingList";
-NSString* const kUpdatePasswordUIEnabled = @"UpdatePasswordUIEnabled";
+NSString* const kUpdatePasswordUIDisabled = @"UpdatePasswordUIDisabled";
 NSString* const kEnableQRCodeReader = @"EnableQRCodeReader";
 NSString* const kEnableNewClearBrowsingDataUI = @"EnableNewClearBrowsingDataUI";
 }  // namespace
@@ -140,8 +140,8 @@ bool IsPhysicalWebEnabled() {
 }
 
 bool IsUpdatePasswordUIEnabled() {
-  return [[NSUserDefaults standardUserDefaults]
-      boolForKey:kUpdatePasswordUIEnabled];
+  return ![[NSUserDefaults standardUserDefaults]
+      boolForKey:kUpdatePasswordUIDisabled];
 }
 
 bool IsQRCodeReaderEnabled() {