Move dexpreopting to Soong

Move the dexpreopting logic into Soong.  Make modules will be
dexpreopted by executing the Soong logic in the standalone
dexpreopt_gen binary, which will generate scripts that will
perform dexpreopting for each module.  Export global configuration
as JSON to $OUT/dexpreopt.config, which will be used by
dexpreopt_gen and Soong, and per-module JSON configuration that
will be used by dexpreopt_gen.

Bug: 119412419
Bug: 120273280
Test: no differences to dexpreopt outputs on aosp_sailfish system/,
      only expected changes to dexpreopt outputs on system_other
      (.vdex files for privileged Soong modules no longer incorrectly
      contain .dex contents).
Change-Id: I59b20c931ee3e5a8d35eb30da4148691c5095502