use MimeTypeMap from android webkit to check if the json MimeType is unsupported

Author: dev-victoria

app/src/main/java/org/schabi/newpipe/local/subscription/SubscriptionFragment.kt

@@ -13,6 +13,7 @@ import android.view.MenuItem
 import android.view.SubMenu
 import android.view.View
 import android.view.ViewGroup
+import android.webkit.MimeTypeMap
 import android.widget.Toast
 import androidx.activity.result.ActivityResult
 import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult
@@ -460,6 +461,14 @@ class SubscriptionFragment : BaseStateFragment<SubscriptionState>() {
     }
 
     companion object {
-        const val JSON_MIME_TYPE = "application/json"
+        val JSON_MIME_TYPE = getMimeType()
+
+        private fun getMimeType(): String {
+            val mimeTypeJson = MimeTypeMap.getSingleton().getMimeTypeFromExtension("json")
+            return if (mimeTypeJson.isNullOrBlank())
+                "application/octet-stream"
+            else
+                mimeTypeJson
+        }
     }
 }