Android: Resolves #680: New: Allow self-signed certificates (#1466)

* Allow User-added CAs in Android

This will enable connecting to servers with self-signed certificates on
android as per issue #680.

Implemented as per:
- https://android-developers.googleblog.com/2016/07/changes-to-trusted-certificate.html
- https://github.com/facebook/react-native/issues/20488

* Allow User-added CAs in Android

This will enable connecting to servers with self-signed certificates on
android as per issue #680.

Implemented as per:
- https://android-developers.googleblog.com/2016/07/changes-to-trusted-certificate.html
- https://github.com/facebook/react-native/issues/20488

ReactNativeClient/android/app/src/main/AndroidManifest.xml

@@ -37,7 +37,9 @@
 		android:allowBackup="true"
 		android:label="@string/app_name"
 		android:icon="@mipmap/ic_launcher"
-		android:theme="@style/AppTheme">
+		android:theme="@style/AppTheme"
+		android:networkSecurityConfig="@xml/network_security_config"
+		>
 
 		<!-- ============================= -->
 		<!-- START RN-push-notitication    -->

ReactNativeClient/android/app/src/main/res/xml/network_security_config.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <base-config>
+        <trust-anchors>
+            <certificates src="system"/>
+            <certificates src="user"/>
+        </trust-anchors>
+    </base-config>
+</network-security-config>