[react-native-vector-icons] fix: Icon style (#38639)

types/react-native-vector-icons/Icon.d.ts

@@ -55,7 +55,7 @@ export interface IconButtonProps extends IconProps, TouchableHighlightProps, Tou
    *
    * @default {marginRight: 10}
    */
-  iconStyle?: ViewStyle;
+  iconStyle?: TextStyle;
 
   /**
    * Style prop inherited from TextProps and TouchableWithoutFeedbackProperties

types/react-native-vector-icons/index.d.ts

@@ -3,6 +3,7 @@
 // Definitions by: Kyle Roach <https://github.com/iRoachie>
 //                 Tim Wang <https://github.com/timwangdev>
 //                 Robert Ying <https://github.com/robertying>
+//                 Jesse Katsumata <https://github.com/Naturalclar>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.8