Do not create a browser bound key when off the record. (1/2)

Before this change, while creating a passkey with the payment extension
enabled, a browser bound key was created in regular and off the record
contexts. After this change, the browser bound key is not created in
off the record contexts.

Browser bound keys are behind the flag
chrome://flags/#enable-secure-payment-confirmation-browser-bound-key.

Bug: 377278827, b:407760471
Change-Id: I7f7f32edca98f69871c19e755c6d561e1b2fbec5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6570849
Commit-Queue: Slobodan Pejic <slobodan@chromium.org>
Reviewed-by: Kavita Soni <kavitasoni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1464773}