fix(material-experimental/mdc-form-field): color inputs not working

Fixes that the `color` type inputs didn't work due to a style override we had on top of MDC.

Author: crisbeto

src/material-experimental/mdc-form-field/_mdc-text-field-structure-overrides.scss

@@ -30,6 +30,13 @@
     height: auto;
   }
 
+  // Color inputs are a special case, because setting their height to
+  // `auto` will collapse them. The height value is an arbitrary number
+  // which was extracted from the user agent styles of Chrome and Firefox.
+  .mat-mdc-form-field-control[type='color'] {
+    height: 23px;
+  }
+
   // Root element of the mdc-text-field. As explained in the height overwrites above, MDC
   // sets a default height on the text-field root element. This is not desired since we
   // want the element to be able to expand as needed.