[improvement] make props less magic (#3775)

src/submit-bar/index.tsx

@@ -94,17 +94,14 @@ function SubmitBar(
 
 SubmitBar.props = {
   tip: String,
-  tipIcon: String,
   label: String,
+  price: Number,
+  tipIcon: String,
   loading: Boolean,
   disabled: Boolean,
   buttonText: String,
   suffixLabel: String,
   safeAreaInsetBottom: Boolean,
-  price: {
-    type: Number,
-    default: null
-  },
   decimalLength: {
     type: Number,
     default: 2