Fix unit test engine↔parser assignment

In the unit tests, the engine is given a parser, but the parser is not
being associated back with the engine. So in some cases, that could lead
to *another*, default engine being created for certain operations.

Fix that.

Change-Id: I79995c2635d9e470931b84dc1854dae26772bbe3
Merge "Fix unit test engine↔parser assignment"