Allow debug build besides release build

OpenKeychain/src/main/res/xml/sync_adapter_desc.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <sync-adapter xmlns:android="http://schemas.android.com/apk/res/android"
     android:contentAuthority="com.android.contacts"
-    android:accountType="org.sufficientlysecure.keychain.account"
+    android:accountType="@string/account_type"
     android:supportsUploading="false"
     android:userVisible="true"
     android:allowParallelSyncs="false"