Note: In case, if you want to delete a file or folder from Google Drive Trash, then here are the steps:
Go to "Trash" in Google Drive. Right click on the one you want to delete.
Now, you can see two options - Restore and Delete forever. Hit "Delete forever." In the confirmation popup, click "Delete Forever."
Go to "Trash" in Google Drive. Select the one you want to delete by long pressing it.
Now, hit the "Trash Can" icon at the bottom. In the confirmation popup, tap "Delete Forever."
Another important thing to note: Select the ones you want to remove from Trash and then apply the above steps to delete multiple files and/or folders at once.