add feature to example

KeychainExample/App.js

@@ -128,6 +128,7 @@ export default class KeychainExample extends Component {
                 <Text style={styles.buttonText}>Save</Text>
               </View>
             </TouchableHighlight>
+
             <TouchableHighlight
               onPress={() => this.load()}
               style={styles.button}
@@ -136,6 +137,7 @@ export default class KeychainExample extends Component {
                 <Text style={styles.buttonText}>Load</Text>
               </View>
             </TouchableHighlight>
+
             <TouchableHighlight
               onPress={() => this.reset()}
               style={styles.button}
@@ -144,6 +146,22 @@ export default class KeychainExample extends Component {
                 <Text style={styles.buttonText}>Reset</Text>
               </View>
             </TouchableHighlight>
+
+            <TouchableHighlight
+              onPress={async() => {
+                if (Platform.OS !== 'android') {
+                  alert('android-only feature');
+                  return;
+                }
+                const level = await Keychain.getSecurityLevel();
+                alert(level)
+              }}
+              style={styles.button}
+            >
+              <View style={styles.load}>
+                <Text style={styles.buttonText}>Get security level</Text>
+              </View>
+            </TouchableHighlight>
           </View>
         </View>
       </KeyboardAvoidingView>

KeychainExample/android/build.gradle

@@ -2,9 +2,9 @@
 
 buildscript {
     ext {
-        buildToolsVersion = "27.0.3"
+        buildToolsVersion = "28.0.0"
         minSdkVersion = 16
-        compileSdkVersion = 27
+        compileSdkVersion = 28
         targetSdkVersion = 26
         supportLibVersion = "27.1.1"
     }