fix: empty draft when the message is sent

[dnlsilva]

Proposed changes

Currently, after sending the message, if you close the app abruptly the draft is not deleted, adding the function to save the draft after sending the message solves the problem.

Issue(s)

How to test or reproduce

• Send a message and close the app quickly, the draft should be removed.

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Documentation update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules

Further comments

Jira: CORE-116