These are the changes to init and init.rc necessary to
support booting with and encrypted /data filesystem.
A corresponding change to init.<device>.rc goes along
with this change.
Change-Id: I0c7e2cc39568358014a82e317735c0eae14dd683
If any child processes exit before signal_init, they won't get reaped
unless another child process exits after signal_init. Calling
handle_signal from signal_init forces them to be reaped immediately.
Change-Id: I459cfbfe6cf00f29454c62a8c840baf21cb1fb03