chore(example): add network_security_config to support proxy

Added the network_security_config configuration to support proxy tools for android

Author: abdelhamid-f-nasser

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

@@ -16,6 +16,7 @@
         android:label="Instabug - Flutter"
         android:name="${applicationName}"
         android:icon="@mipmap/ic_launcher"
+        android:networkSecurityConfig="@xml/network_security_config"
         android:usesCleartextTraffic="true">
         <activity
             android:name=".MainActivity"

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

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <domain-config cleartextTrafficPermitted="true">
+        <domain includeSubdomains="true">localhost</domain>
+    </domain-config>
+    <base-config>
+        <trust-anchors>
+            <certificates src="system" />
+            <certificates src="user" />
+        </trust-anchors>
+    </base-config>
+</network-security-config>