switch media.can_download flag to a db value

app/sync/migrations/0018_media_can_download.py

@@ -0,0 +1,18 @@
+# Generated by Django 3.1.4 on 2020-12-09 08:40
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('sync', '0017_auto_20201208_0521'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='media',
+            name='can_download',
+            field=models.BooleanField(db_index=True, default=False, help_text='Media has a matching format and can be downloaded', verbose_name='can download'),
+        ),
+    ]