Autofocus first input for Search Token and Custom Token (#9562)

ui/app/pages/add-token/add-token.component.js

@@ -232,6 +232,7 @@ class AddToken extends Component {
           onChange={(e) => this.handleCustomAddressChange(e.target.value)}
           error={customAddressError}
           fullWidth
+          autoFocus
           margin="normal"
         />
         <TextField

ui/app/pages/add-token/token-search/token-search.component.js

@@ -74,6 +74,7 @@ export default class TokenSearch extends Component {
         onChange={(e) => this.handleSearch(e.target.value)}
         error={error}
         fullWidth
+        autoFocus
         startAdornment={this.renderAdornment()}
       />
     )