Add integration test for testing the arch variant passed to cc modules included in APEXES.

Resend aosp/2350557, with minor change on line 65 of apex_cc_module_arch_variant_tests.sh.
The pattern was:
  '.*android_target.*: ([0-9]+)$'
and is changed to:
  '.*opt-ST.*: ([0-9]+)$'
since the Bazel output directory name has been changed.

Bug: 258422889
Test: build/soong/tests/run_integration_tests.sh
Change-Id: Ib114bc0084d8ea2cd232d6478cc81a039b138bc4