add Image border*Radius tests

Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/20264

Differential Revision: D9228814

Pulled By: TheSavior

fbshipit-source-id: cad4c15e8070c7ab2023c20045b82f7ab3f994cf

RNTester/js/ImageExample.js

@@ -443,6 +443,30 @@ exports.examples = [
             style={[styles.base, styles.leftMargin, {borderRadius: 19}]}
             source={fullImage}
           />
+          <Image
+            style={[styles.base, styles.leftMargin, {borderTopLeftRadius: 20}]}
+            source={fullImage}
+          />
+          <Image
+            style={[styles.base, styles.leftMargin, {
+              borderWidth: 10,
+              borderTopLeftRadius: 10,
+              borderBottomRightRadius: 20,
+              borderColor: 'green',
+            }]}
+            source={fullImage}
+          />
+          <Image
+            style={[styles.base, styles.leftMargin, {
+              borderWidth: 5,
+              borderTopLeftRadius: 10,
+              borderTopRightRadius: 20,
+              borderBottomRightRadius: 30,
+              borderBottomLeftRadius: 40,
+              borderColor: 'red',
+            }]}
+            source={fullImage}
+          />
         </View>
       );
     },