Prevent implicit outputs created during dexpreopt_config.zip

$PRODUCT_OUT/dexpreopt_config.zip is created by zipping all the
dexpreopt configs of individual apps. These config files are created in
$PRODUCT_OUT/dexpreopt_config, and this dir is as used as -C for
soong_zip.

In the current implementation, this build action also implicitly copies
global configuration files dexpreopt.config and dexpreopt_soong.config
into $PRODUCT_OUT/dexpreopt_config with the intent of being included in
the resultant zip file. These implicit outputs are unknown to ninja.

This CL prevents creation of these implicit outputs.
out/soong/dexpreopt_soong.config and
out/soong/dexpreopt_<arch>/dexpreopt.config is now passed directly to
soong_zip via -f.

Bug: 333316620
Test: m out/target/product/vsoc_x86_64/dexpreopt_config.zip # no longer
bit identical since the relative order changes, dexpreopt(_soong).config
now appears at the bottom of the zip
Test: zipcmp dexpreopt_config.zip.before dexpreopt_config.zip.after # no
diffs

Change-Id: Ib30c9a5c436e263231f9688129ab94664277b841