Reland "Use inline default initialization for RevocationPolicy members"

This time also make the members regular bools instead of bitfields.
There's no real need for these to be bitfields and default member
initializers for bitfields requires C++20.

Partially a re-land of https://crrev.com/c/4455489
Partially a revert of https://crrev.com/c/4527295

Change-Id: I628ccfc316597161919024023ddf9893587401c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4545315


Commit-Queue: Matt Mueller <mattm@chromium.org>
Reviewed-by: Bob Beck <bbe@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1145707}