Add and enable flag for writing appcomppat system properties

Currently, init always writes a copy of system properties to
/dev/__properties__/appcompat_override. This behavior is now conditional
on this flag. This flag is being enabled to keep current behavior the
same.

Bug: 331307495
Test: manual
Ignore-AOSP-First: Merge conflict between internal and aosp
Change-Id: I0807597f26b31aab416aa3a0a19918e9d6869695