[FIX] l10n_in: Use partner autocomplete data to set GST Treatment

Before this commit:
We used to set `regular` treatment when using QR Vendor Scan
or Fetching bill with IRN

After this commit:
We use the GST Treatment received from Partner Autocomplete
to set the GST Treatment

task-none

closes odoo#234136

Signed-off-by: Josse Colpaert (jco) <[email protected]>

Author: hamo-odoo

addons/l10n_in/models/res_partner.py

@@ -91,7 +91,7 @@ def _l10n_in_get_partner_vals_by_vat(self, vat):
             'country_id': partner_data.get('country_id', {}).get('id'),
             'state_id': partner_data.get('state_id', {}).get('id'),
             'company_type': 'company',
-            'l10n_in_gst_treatment': 'regular',
+            'l10n_in_gst_treatment': partner_data.get('l10n_in_gst_treatment', 'regular'),
         })
         return partner_data