Ports more manifest tests to unified syntax (#3986)
Ports more manifest tests to unified syntax (#3986)

* Update more manifest tests to use unified syntax

* Set default syntax on and de-duplicate slandles syntax tests

PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs