* Create new activity to encapsulate account upgrade
* Populate it with a list of legacy accounts, and progress bars for each
* Sidestep Welcome when there are legacy accounts to convert
* Super lightweight account migration:
- Account login info only
- no folders, messages, or attachments
* Scrub out old data
* Return to Welcome screen
As noted, the copies working (useable) POP & IMAP accounts, but does
not try to deal with folders, messages, or attachments.
Bug: 2065528
842ac04828