Use AndroidProducts.mk list from Soong's finder

This saves ~300ms from get_build_var on our internal tree (1.3s ->
1.0s). On AOSP, it only saves ~60ms (0.60s -> 0.54s).

It's also ran during lunch, and twice during every build (though the
second time it was run with Kati's find emulator, which significantly
reduces the overhead).

Bug: 78020936
Test: diff out/.module_paths/AndroidProducts.mk.list with existing find
      results
Change-Id: I195b2840854122e41275e24e886ca8c8cda13dac