Add network security config

* Allow cleartext on Android 9+
* Allow user CAs on Android 7+

app/src/main/AndroidManifest.xml

@@ -86,6 +86,7 @@
   <application
     android:allowBackup="true"
     android:fullBackupContent="@xml/backup_config"
+    android:networkSecurityConfig="@xml/network_security_config"
     android:icon="@mipmap/ic_launcher_blue"
     android:label="@string/app_name"
     android:manageSpaceActivity="com.todoroo.astrid.core.OldTaskPreferences"

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

@@ -0,0 +1,6 @@
+<base-config cleartextTrafficPermitted="true">
+    <trust-anchors>
+        <certificates src="system" />
+        <certificates src="user" />
+    </trust-anchors>
+</base-config>