Private Browsing button state is not known in TalkBack

[eeejay]

Steps to reproduce

1. With TalkBack on go to Private Browsing button. You will hear: "Enable Private Browsing, button"
2. Activate button (double tap)
3. Private browsing window appears, go to Private Browsing. You will hear "Enable Private Browsing, button".

Expected behavior

When in Private browsing, it should say "Disable Private Browsing, button".

Actual behavior

It says "Enable Private Browsing, button".

Device information

• Android device: Pixel
• Fenix version: master/nightly

Aside

We need to figure out a prominent way for TalkBack users to know they are in private browsing. Right now, they would need to check the state of this button or read the private browsing copy in the private browsing home screen.

That should probably be a followup issue.

┆Issue is synchronized with this Jira Task

[eeejay]

Something that seems like a general usability thing, but is harder for TalkBack users: The private browsing button switches back and fourth between the private and non-private session. A user might expect "disabling" the private session would delete it. Instead it persists until the next time a user "enables" private browsing. Is this a feature or bug?

If its a feature maybe what we really need is a "enter/exit private browsing" instead of enable/disable. Don't know. That might help a bit for TalkBack users, but for sighted users that toggle-like button might still be confusing.