init: Remove the DebugRebootLogging() function

The DebugRebootLogging() function was introduced to help with
root-causing b/150863651. Remove this function since this logging
functionality is no longer needed. Also remove the functions and methods
that are only used by DebugRebootLogging().

Change-Id: Ia150604c6cd70f42b13d655ba43b95445a55b6e2
Signed-off-by: Bart Van Assche <bvanassche@google.com>