[Bug] Selecting text to set as spoiler text deletes the text

1. Type some text.
2. Highlight that text.
3. Press the spoiler button.

Expected result: It should put the text in the spoiler body.

Current result: It deletes the text completely and just puts the default spoiler template, requiring you to undo to retrieve your typed text (sucks for keyboards that don't have an "undo" button; go HeliBoard!).