PHILADELPHIA — After Frans and his wife came to Philadelphia from Indonesia in the mid-2000s, they lived in fear that their young son would accidentally spill the family secret and get them all deported: They were in the United States illegally. “We always told our son, no matter how close you are, you do not share anything,” said Frans, who is in his 50s and asked that his full name not be published. “You cannot open the door to whoever rings our bell or talk to any strangers.” The couple abandoned an upscale life in their homeland to move into the shadows here, trading a big house and a thri…