So that it can be used in the bazel implementation.
Bug: 268006095
Test: m nothing, check that it's in out/soong/soong_injection
Change-Id: I1520dd874076dee7fa083648d0790b060d658e5a
apex_toolchain through soong_injection.
This is necessary to keep both Bazel and Soong in sync.
Test: presubmit
Bug: 238723069
Fixes: 238153998
Change-Id: Ibf4a8ed91d358dc7800c10e4112485a52f0606bb