Move properties get/set code to osi

Currently we use Android-specific property_get and property_set
through the code. This patch adds osi_property_get and osi_property_set
that is encapsulating all external dependencies. This is step further
for errorless compilation on linux.

Bug: 27324453
Change-Id: I97c34344617a5855b683328bcd196a21a2fae6f9