switch to using DIST_DIR env var for dist

the dist dir should not be passed in as an argument, it should be picked
up from the environment.

Test: ./build/make/ci/build_test_suites --target_product aosp_x86_64 --target_release trunk_staging --with_dexpreopt_boot_img_and_system_server_only
Bug: 314171817
Change-Id: I32c007677cf1d81bb7b263b5c69e5510bf8dccfe