While holding power key to trigger reset, the bootreason is
reboot_longkey and also stored in RAMDUMP_MSG.txt.
Bug: 79553608
Bug: 110231796
Change-Id: I17ec89337d754e83d7dd218430af1f92f72173cb
Signed-off-by: Chungjui Fan <chungjuifan@google.com>
Signed-off-by: Chris Fries <cfries@google.com>