Prepare /data/property before load_persist_props

Without the directory (this happens on the very first boot),
load_persist_props can't create an initial version of
/data/property/persistent_properties (probably empty). This leads to
persisting all in-memory "persist.*" properties later when a persistent
property is set. This is regression from Android S because persistent
props from, for example, build.prop will be persisted even when there's
no process to explicitly setprop.

Bug: 242264580
Bug: 243958304
Test: launch cuttlefish and verify that there's no props from build.prop
Merged-In: I5819a97750e4d5d1ee5a7c308bf944c7aeab2f90
Change-Id: I5819a97750e4d5d1ee5a7c308bf944c7aeab2f90
(cherry picked from commit 95614963)