[Authenticator] Allow specifying string messages for arbitrary exception types

[mattcreaser]

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• I have searched for duplicate or closed issues.

Which UI component is this feature-request for?

Authenticator

Please include any relevant guides or documentation you're referencing

No response

Please describe your feature-request in detail.

On the Swift Authenticator, you can specify string content for any cognito error by using a specific string key, even if Authenticator itself doesn't have any logic for that case. We should implement a similar system on Android.

1. When resolving the string content for an error scenario, first check to see if application has defined a specific string for that exception.
2. If not, use the default string specified in Authenticator.

The list of exceptions we can expect to receive can be found here. We can transform the exception type into a string resource ID using some known algorithm, something like:

1. Strip the "Exception" suffix
2. Transform the remaining name to snake_case
3. Prepend amplify_ui_authenticator_error_

This would result in e.g. ParseTokenException resolving to a string R.string.amplify_ui_authenticator_error_parse_token that could be defined in the application resources to set the content for this exception.

Initialization steps (if applicable)

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Code Snippet

// Put your code below this line.

amplifyconfiguration.json

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Additional information and screenshots

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