Start running some disabled tests again on Mac OS.

Start running some disabled tests again on Mac OS.

These tests were disabled when trying to get CI working on Mac OS
because they asserted or crashed.  Now that CI is working well on Mac
OS, start running these tests again, initially as insignificant tests.
CI results will then be used to determine whether the tests can be made
significant.

Change-Id: Ife411e6b8c84ade45c865ef35f3ae0071d6f8d2b
Reviewed-by: Sergio Ahumada <sergio.ahumada@nokia.com>
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>