[Passwords] Show suggestions after generation rejection

In https://crrev.com/c/6087811 the generation logic was modified to
prevent generation popup from re-appearing after it was rejected by
clicking "Choose your own".

In a scenario where generation is triggered from the autofill popup
with password suggestions, the rejection should rather not cause the
popup with suggestions to not re-appear. This CL:
* fixes that by passing `generation_rejected` bit from renderer to
browser, allowing popup with suggestions to be displayed in case there
are any [1]
* additionally cleans up the flag from chrome_password_manager_client
and interactive_ui_test

Before: https://drive.google.com/file/d/1_R6e708zg5gQmUpbJdRnMhq-35_hUQCQ
After: https://drive.google.com/file/d/15S2DrEYL1JSm8YJqUt1P1J0keETD79qP

[1] https://source.chromium.org/chromium/chromium/src/+/main:chrome/browser/password_manager/chrome_password_manager_client.cc;l=1458;drc=a08bffe87ff70f2049c4443d50583eae5c17f927

Bug: 41492898
Change-Id: I2f8d344ab28fab1fc32f1c9df13da8afa7cf6cbd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6149492
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Rafał Godlewski <rgod@google.com>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1404754}