Build license metadata files in Soong

Soong has enough information to build the license metadata files
without resorting to the fixups required in Make.

Bug: 207445310
Test: m checkbuild
Change-Id: I8e74108376162b8fdb87ba098ebe94350aa1f7c4
diff --git a/android/Android.bp b/android/Android.bp
index a20aedc..da36959 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -47,6 +47,7 @@
         "image.go",
         "license.go",
         "license_kind.go",
+        "license_metadata.go",
         "license_sdk_member.go",
         "licenses.go",
         "makefile_goal.go",