[ Merge of http://go/wvgerrit/152650 ]
There are two LOGEs in device_files.cpp that would frequently trigger
during testing despite the condition they were logging being totally
normal. The files were not present because the device had never had to
write them yet. This patch downgrades these bengin errors to warnings
to reduce log spam.
Test: build_and_run_all_unit_tests.sh
Bug: 236317198
Change-Id: I56f9d477f8a6b26635f0eb4a6b7c636e866381d3