Allow multiple emulated storages at the same time.

Only do multiuser mapping for primary emulated storage as per google docs.
Allow all non-primary emulated storage to have id other than 0 so that
it could be distinguished from the primary volume.

Change-Id: I7b70b9067fd6211055fb9074710f48107d7b0e8e
T-Mobile required login tethering fix
Revert "Allow multiple emulated storages at the same time."

This reverts commit ded476c7a956b38298c3abc6a204b12556a538d1.

NOTE: after about a few failed attempts and cross referencing error start dates, figured this caused sys ui errors upon rom boot.
ScreenShot QuickTrash
Merge remote-tracking branch 'github/jb43' into jb43-r2.2