Frontend: Add a helpful validation message when masked variable contains newline characters
Release notes
Problem to solve
When creating a new project or group variable, masked variables can't contain newline characters
We show the same generic error that is unhelpful in resolving the problem when unsupported characters are used for a masked variable value.
The error just says This variable can't be masked, and doesn't explain why.
Proposal
When attempting to mask a variable with value that uses newline characters, show a clear error message that allows you to fix the problem.
Value cannot contain newline characters.
Intended users
Feature Usage Metrics
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