ANDROID: vendor_hooks: Add vendor hooks for getting printk messages

When sudden reset by watchdog occurs, kernel log is very helpful.
But the log has saved structure type in log_buf.
So we want to collect the log on runtime to string format at other
reserved memory.

Bug: 167766040

Change-Id: Ic9686acc7c284e2ab81395fb9cc076fafe142bf9
Signed-off-by: Changki Kim <changki.kim@samsung.com>