Move ManageAccountsSettings into Settings.

- Add activity-alias for the Activity.
- Copy the Activity from AccountsAndSyncSettings.
- Fragmentize ManageAccountsSettings.
- Remove dependency toward AccountPreferenceBase, which is
  used in AccountsAndSyncSettings widely.
- Add missing implementation derived from AccountPrefernceBase.
- Copy dependent drawables.
- Copy dependent xmls
- Copy AccountPrefernce.java.
- Copy strings, adding CHAR LIMIT.
- Remove the logic which remove the preference when its destination
  Activity is missing. We already have the destination as
  Fragment, and it never disappear.

Change-Id: Id41c63d7064aebeaae31bcd84bf4fd20a5636dfe
26 files changed