*flow_action_components* - _SendBetterEmail _ - Flow action variables seem to persist for html/plaintext body even after being cleared

[starkguerraj]

Steps to reproduce the behavior:

1. During Flow creation, enter any values for the HTML or plaintext body with the Specify Body here button selected.
2. Remove values
3. Use Email Template and specify proper parameters.
4. Debug/execute flow to receive error.

Expected behaviour

Email should send using template and not fail due to html or plaintext body being added and removed.

Actual behaviour

Error is thrown, value seems to be interpreted as a an empty string instead of a null by the SendBetterEmail class resulting in the error:

'You're trying to pass in both a plaintext/html body and a template ID. Gotta pick one or the other. Make sure you're not confusing the Text Template resources in Flow, (which you can pass into either the HTMLBody or the plainTextBody) with the templateID, which represents a Salesforce Email Template (either Classic or Lightning).';