Bug 963331 - [B2G][email] Recieved emails can be moved to 'Local Drafts'  folder. r=asuth

land https://github.com/mozilla-b2g/gaia/pull/21720 squashed

creating this pull request to squash the two commits in that pull request and for landing expediency.  No changes have occurred and the gelam landing of https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/321 did not result in diff changes.