Add build flag on platform dependent change

The commit a9b79dd7 is a platform dependent change. Its external
dependencies does not merge to R. Firstly, mainline modules are built
from internal branch which stay in Android R. Secondly, we want module
code in AOSP (S on going) and internal branch for mainline modules are
synchronized. Thus, it needs a build flag to satisfy both branches.

Bug: 168163123
Test: build pass on aosp and mainline release branch
Change-Id: I5c1cf56fe2bd35afecdad0a3005f5c34b2246acf