Add *AsUser() calls where appropriate for multi-user support.

Although telecom always runs as system user, it binds to apps in the
user space and so needs to interact with apps with the current user
explicitly.  This change fixes areas that neglected to do that.

Bug: 27161171
Change-Id: I55a4f612c9b38d4e448c346173845a79a926c695
7 files changed