Allow vendor_init_settable for persist.sys.sf.native_mode

A default value of persist.sys.sf.native_mode could be set by SoC
partners in some devices including some pixels.
So it should have vendor_init_settable accessibility.

Bug: 74266614
Test: succeeded building and tested with a pixel device with
PRODUCT_COMPATIBLE_PROPERTY_OVERRIDE=true.

Change-Id: I5d7a029f82505983d21dc722541fb55761a8714d
Merged-In: I5d7a029f82505983d21dc722541fb55761a8714d
(cherry picked from commit 0dc35873)