Move dumping of oat file status inside of the OatFileAssistant.

Rather than exposing what could otherwise be internal to the
OatFileAssistant, move the logic for dumping a human readable
representation of the status of the oat files inside the
OatFileAssistant.

Bug: 30937355
Test: oat_file_assistant_test

Change-Id: I79c6cc1286a822f1dbe0035be934a2be4792563c
3 files changed