Change self recovery log level from wtf to error

Reasons:
1. These recovery events are reported to metrics as well.
2. These recovery events are not severe and don't impact
user experiecne.
3. We usually can't get useful information from the wtf log
snippets.

Bug: 66996979
Test: compile, unit tests
Change-Id: I713a243927bf935aaf356289be42389f1ba0d5ea
1 file changed