Clearing obsolete cloneUserId from CloneBackend.

When cloned user is removed from device, the previous clonedUserId
present with the CloneBackend instance becomes obsolete, and does
not update to reflect the new clonedUserId, when the cloned user is
re-created.
To fix this we set cloneUserId to -1 when cloned user is removed,
causing CloneBackend#installCloneApp to update clonedUserId when
the cloned profile is re-created.

Bug: 280431074, 275062025
Test: Manual by flashing the local build.
Change-Id: If0d7960998865b4081502e84d0d4125b3b05c69c