Allow self signed certificates

Specially useful for self hosted instances that are not reachable over the
internet or similar

Closes #116

Author: rolandgeider

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

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config xmlns:tools="http://schemas.android.com/tools">
+    <base-config>
+        <trust-anchors>
+
+            <!-- Trust preinstalled CAs -->
+            <certificates src="system" />
+
+            <!-- Additionally trust user added CAs -->
+            <certificates
+                src="user"
+                tools:ignore="AcceptsUserCertificates" />
+        </trust-anchors>
+    </base-config>
+</network-security-config>