improved orbot notify, added periodic sync

OpenKeychain/src/main/res/xml/keyserver_sync_adapter_desc.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
-    android:contentAuthority="org.sufficientlysecure.keychain.debug.provider"
+    android:contentAuthority="@string/provider_content_authority"
     android:accountType="@string/account_type"
     android:supportsUploading="false"
     android:userVisible="true"