Reject an incoming call with a text message

[jeevanpulluru]

Checklist

• [x] I am using the latest version - 1.09
• [] I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• [] This issue contains only one feature request. I will open one issue for every feature I want to request.

Please add an option to reject a call with a text message

Once we reject a call with a text message, the other person tends to leave a text message, so that we can call them again. This works as a reminder for us to call a particular person after some time