Update New Member Checklist box-shadow

Update the shadow to allow it to contrast more against the rest of the
user interface. The adjustments are:
- Set the shadow offset to (0,0) so that the shadow is visible on all
edges of the checklist
- Update shadow length to be 1em instead of 0.75em, and express it in em
unites as well
- Multiply the opacity value of the shadow by 2.

PER-9650: Increase border shadow on checklist

src/app/user-checklist/components/user-checklist/user-checklist.component.scss

@@ -8,7 +8,7 @@
   width: 22.5em;
   border-radius: 5px;
   background-color: #fff;
-  box-shadow: 0px 4px 8px 0px #00000026;
+  box-shadow: 0px 0px 1em 0px #0000004c;
   padding: 0.5em 1.25em;
   font-family: 'Open Sans', sans-serif;
 }