(cherry pick from commit d4b061bde2)
- This is considered an Android Private function, not exported
for general use.
- goal is to record a file's content into a series of log
messages into pmsg, to be retrieved after a reboot for
transfer to a persistent location.
- filename reference is converted to a tag-unique
"<dirbase>:<filebase>".
- buffer and length representing the filename contents are
recorded, along with a sequence number placed into the nsec
time field to ANDROID_LOG_PMSG_FILE_MAX_SEQUENCE.
- Add a gTest for this function.
Bug: 27176738
Change-Id: If93df3ae8bfc1bb75516d4a1fd8dae0301af644b
10bdf61e5f