Fix default tooltip color (#11633)

ui/components/ui/info-tooltip/info-tooltip.js

@@ -17,7 +17,7 @@ export default function InfoTooltip({
   containerClassName,
   wrapperClassName,
   wide,
-  iconFillColor = '',
+  iconFillColor = '#b8b8b8',
 }) {
   return (
     <div className="info-tooltip">

ui/pages/swaps/fee-card/__snapshots__/fee-card.test.js.snap

@@ -65,7 +65,7 @@ exports[`FeeCard renders the component with initial props 2`] = `
           >
             <path
               d="M5 0C2.2 0 0 2.2 0 5s2.2 5 5 5 5-2.2 5-5-2.2-5-5-5zm0 2c.4 0 .7.3.7.7s-.3.7-.7.7-.7-.2-.7-.6.3-.8.7-.8zm.7 6H4.3V4.3h1.5V8z"
-              fill=""
+              fill="#b8b8b8"
             />
           </svg>
         </div>