Investigate and remove feature flag for WebAuthn

[jonalmeida]

We added a feature flag and this ticket is to track the removal of the flag to let it ride the trains.

Tracking feature: #1340

Potential Blockers

• #18347 - [Bug] WebAuthn implementation doesn't allow retry
• #17688 - Support Opting-in to Direct Attestations on Android
• BZ-1711541 - PublicKeyCredential.isUserVerifyingPlatformAuthenticatorAvailable returns false even when supported
• BZ-1689612 - WebAuthn does not specify the authenticator type during attestation

┆Issue is synchronized with this Jira Task

[sbrl]

....but the new Firefox for Android beta doesn't support Webauthn, does it? At least it's never worked for me.

[mhalano]

@sbrl For now, I think it just works in Firefox Nightly. I opened another issue to enable the feature in beta since the nightly has the feature for some time.

[jonalmeida]

With the two main GV bugs fixed, we should let this ride the trains.

The remaining two bugs should be fixed, but they are not blocking core functionality.

[mhalano]

Unfortunately, the repo was already branched to 91.0 release, so I think this change will come just during 92.0 cycle. Although, better later than never, should I say.

[Chaz6]

I would really like to be able to use my FIDO U2F keys with firefox on android, so the sooner this gets landed the better! Thank you.

[mhalano]

@Chaz6 Seems it will be released in the Firefox 92.0.

[mhalano]

I just received the 92.0 version and I can confirm WebAuthn is working. Thanks everybody.

[Chaz6]

@Chaz6 Seems it will be released in the Firefox 92.0.

Thank you!