Add unit basic unit tests for tenant_isolation

This commit adds some basic unit test coverage for the tenant isolation
code. It doesn't provide complete coverage yet, but to avoid having
a giant patch this is the first chunk.

Partially implements bp unit-tests

Change-Id: Ic7d5368a4c0b8c2eeb61a73481f630ba04ee70b0
Add network credential unit testing

This commit adds some of the missing coverage from the isolated
credentials unit tests. This also adds the unit tests for the alt
user/tenant.

Partially implements bp unit-tests

Change-Id: Id5e7ba3e8d2b74f20651d522efa9856886c64de7
Merge "Add unit basic unit tests for tenant_isolation"
Merge "Add network credential unit testing"