init: initialize property area early at boot

The property service is still started later, but the property area
and the initial boot properties are initialized before the init.rc
file is processed. This allows init.rc files to have access to boot
properties during parsing.

Change-Id: Iae9ed1093c821831a864b39ae6bc697e62b94757
Signed-off-by: Dima Zavin <dima@android.com>