fix bug where sync settings set lost upon upgrade from donut and eclair

to froyo

- intepret a missing syncavble attribute from donut as "unsynced"
  rather than the traditional "true"
- copy the sync settings from the authorities "contacts" and "calendar"
  to "com.android.contacts" and "com.android.calendar" if the latter
  don't already have settings
- delay the database cleanup until after boot completed, which will give
  the GoogleLoginService accounts migration code a chance to run; this
  was causing all the settings to get removed upon a donut to froyo upgrade

Change-Id: I8795e97ba0c9b930d1a50784229ca9ab15dff9d2
http://b/issue?id=2531359