Allow user to keep data when uninstalling (#2506)

Author: Mygod

core/src/main/AndroidManifest.xml

@@ -26,6 +26,7 @@
         android:extractNativeLibs="true"
         android:fullBackupContent="@xml/backup_descriptor"
         android:fullBackupOnly="true"
+        android:hasFragileUserData="true"
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:networkSecurityConfig="@xml/network_security_config"