Add trust anchors for user certificates

One of the requirements for auto backup is the server uses HTTPS.  We need the app to allow self signed certs for use cases where users have used self signed certs

LiftLog.Maui/Platforms/Android/Resources/xml/network_security_config.xml

@@ -3,4 +3,12 @@
     <domain-config cleartextTrafficPermitted="true">
         <domain includeSubdomains="true">10.0.2.2</domain>
     </domain-config>
+    <base-config>
+        <trust-anchors>
+        <!-- Trust preinstalled CAs -->
+        <certificates src="system" />
+        <!-- Additionaly trusted user added CAs -->
+        <certificates src="user"/>
+    </trust-anchors>
+    </base-config>
 </network-security-config>