Wrong toaster message appears after completing rewards onboarding in app
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### Summary
The toaster message that's displayed after a user completes rewards onboarding steps doesn't make sense.
### Steps to reproduce
- Launch the mobile app
- Create a new account
- Use the "Complete to earn tokens" checklist to fulfill all requirements for rewards
### Platform information
- iOS 15.3.x
- Minds v4.22.0
### What is the current *bug* behavior?
Upon completion of the rewards onboarding steps, the user is brought to the newsfeed with a toaster message that reads:
> Your feed should be livelier!
### What is the expected *correct* behavior?
The toaster should read something relevant to completing the onboarding steps.
### Relevant logs and/or screenshots

### Possible fixes
If we already have a relevant string defined, we can use that. Otherwise, we can use this string:
> You've joined rewards!
issue