Purpose / Description

Refactored .csv/.tsv values both in IntentHandler and in ImportFileSelectionFragment.

Fixes

• Fixes refactor: de-duplicate .csv/.tsv values both in IntentHandler and in ImportFileSelectionFragment #17875

Approach

Refactored the code to remove duplication by centralizing the .csv and .tsv MIME type definitions into a shared utility class (MimeTypeUtils).

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner