Design bridge address validation flow on Android

Design estimate

• Complexity: small (1 day)
• Uncertainty: high (2.0) - parts of this task depend on #41187, which is on review
• Total: 2 days (12 hours)
• Actual: 4h 43m

User story

As a user of Tor Browser who lives in a place where regular bridges are blocked
I want to know when a bridge line that I added manually is valid
So I can request another one if necessary

Opportunity statement

Since Tor Browser for Android is a relatively new app in comparison to its version for desktop, it still waits for some advanced improvements. Considering that Tor Browser for desktop currently has real time validation of bridge lines added by users, we should bring this to Android as well, so users can recognize invalid bridge lines that won't help them bypass censorship.

Design scope

• Add visual feedback for invalid bridge lines

Mockups

Figma file (PNGs below this description)

Acceptance criteria

Scenario 1 - Invalid bridge addresses

Given the user pastes at least one invalid bridge addresse in the "Add/Replace bridges" flow
When they tap on the Check icon to save the bridges
Then an error feedback is displayed

Scenario 2 - Valid bridge lines

Given the user pastes only valid bridge addresses in the "Add/Replace bridges" flow
When they tap on the Check icon to save the bridges
Then the browser saves them
And displays a success feedback