switch font-size to inherit

Author: mmalerba

src/lib/core/typography/_typography.scss

@@ -25,7 +25,7 @@
   $caption:     mat-typography-level(12px, 12px, 400),
   $button:      mat-typography-level(14px, 14px, 500),
   // Line-height must be unit-less fraction of the font-size.
-  $input:       mat-typography-level(16px, 1.125, 400)
+  $input:       mat-typography-level(inherit, 1.125, 400)
 ) {
   @return (
     font-family: $font-family,