Override _stringifyPathMatrixAux for UnresolvedInstruction instead of directly change the logic of _stringifyPathMatrixAux of Instruction to prevent breaking existing features.
Override _stringifyPathMatrixAux for UnresolvedInstruction instead of directly change the logic of _stringifyPathMatrixAux of Instruction to prevent breaking existing features.

This cl basically reverts cl/162233310 and also solves the partial routing issue for unresolved instruction. This cl also passes the test attached in the email thread (cl/166181623): https://screenshot.googleplex.com/Xufvod10HcU.png

Tap train result: https://test.corp.google.com/ui#id=OCL:166528171:BASE:166518918:1503698628090:506f2961

PiperOrigin-RevId: 166748219

matanlurey/angular,matanlurey/angular,kevmoo/angular,chalin/angular2,angulardart/angular,angulardart/angular,kevmoo/angular,matanlurey/angular,angulardart/angular,chalin/angular2,chalin/angular2,kevmoo/angular