Where are APN configs saved in Android? I want to know where exactly are stored the APNs that are added by the user on Android. I want to edit them manually using X-plore (or any other root file explorer).
I know that in /system/etc/apns-conf.xml are stored the APN that come preset with the device, but I'm looking for the XML file where the user added APN are stored instead.
I think it depends on your ROM .I recently checked mine and are in the following folder:

/data/data/com.android.providers.telephony/databases/.(telephony.db). You can try opening this .db file as text with a suitable file explorer and see if you can find them. (These are apns in the ROM by default)

Edit

I created a test apn manually and did a search, I learnt that its actually stored here:  /data/data/com.android.settings/shared_prefs/com.android.settings_preferences.x­ml 

(This xml also contains a lot of information found in settings but if you use a keyword search to try and find your manual apn, it will be much faster)

Some of the carrier apns happen to be auomatically added when you insert a new sim card, corresponding to the country, that is why they are stored in telephony database,I reckon. I hardly enter these apns manually even when I change a SIM card.