[RNMobile] Fix: Add default value to format when start and end are un…

…defined (#22741)

* add default vale to format when start and end are undefined

* revert lint changes

packages/rich-text/src/component/index.native.js

@@ -178,7 +178,7 @@ export class RichText extends Component {
 	}
 
 	onFormatChange( record ) {
-		const { start, end, activeFormats = [] } = record;
+		const { start = 0, end = 0, activeFormats = [] } = record;
 		const changeHandlers = pickBy( this.props, ( v, key ) =>
 			key.startsWith( 'format_on_change_functions_' )
 		);