Steps to reproduce:
1. Open attached project
2. Change the smoothness value to max in lwrp
3. Observe that the specular highlight gets infinitely small in LWRP when value is 1
4. Make HDRP and Legacy projects and make a lit material with smoothness of 1
5. Observe the difference in specular highlight behavior, but still leaving the highlight on max value

Expected result: LWRP Lit shader should contain specular highlight when value is 1 for render pipeline consistency

Reproduced in: 2019.3.0a5
Reproduced in packages: 6.5.3