Add visibilities for prebuilts.

These visibilities are intentionally blunt, to allow the prebuilts to
move around for now.

Many of these visibilities may also go away completely again if the
exported binaries are changed to compile internal ART libraries
statically.

Test: v
  1. build/soong/scripts/build-aml-prebuilts.sh art-module-sdk \
     art-module-test-exports conscrypt-module-sdk \
     conscrypt-module-test-exports conscrypt-module-host-exports \
     art-module-host-exports
  2. Unzip out/aml/soong/mainline-sdks/*.zip into separate
     subdirectories under prebuilts/runtime
  3. env SOONG_ALLOW_MISSING_DEPENDENCIES=true m nothing
     (together with the topic of https://r.android.com/1252167)
Bug: 155921753
Change-Id: Id8bbc8aedb0b87e30e9cf3d2a9f34b33cb71756c
8 files changed