Revert "Temporarily comment out art-module-host-exports"

The sdk/module_exports now supports building a single snapshot for
multiple os types so art-module-host-exports should no longer cause
build breakages when building for multiple hosts.

This reverts commit 9f92d9b512c41c17b19f90cc3afa495952e17474.

Bug: 150451422
Test: m nothing
      presubmit will verify the affected builds are no longer broken
Change-Id: I7778536cb4826548fe886de0c7dabb0875c3e8fb
1 file changed