rename NativeSigner-> Parity Signer for android

android/app/src/main/res/values/strings.xml

 <resources>
-    <string name="app_name">NativeSigner</string>
+    <string name="app_name">Parity Signer</string>
 </resources>

android/settings.gradle

-rootProject.name = 'NativeSigner'
+rootProject.name = 'Parity Signer'
 include ':react-native-vector-icons'
 project(':react-native-vector-icons').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-vector-icons/android')
 include ':react-native-secure-storage'