Revert^2 "Filesystem modules follow the installation semantic"

54351867fa0dff593eb61d111d1d7ffb7d3d02f2

Change-Id: I12010c1013fc9dad19d259ba7b0251ac8e8e0907
diff --git a/filesystem/system_image.go b/filesystem/system_image.go
index 5028a49..15cacfb 100644
--- a/filesystem/system_image.go
+++ b/filesystem/system_image.go
@@ -98,5 +98,5 @@
 // Note that "apex" module installs its contents to "apex"(fake partition) as well
 // for symbol lookup by imitating "activated" paths.
 func (s *systemImage) filterPackagingSpec(ps android.PackagingSpec) bool {
-	return ps.Partition() == "system"
+	return s.filesystem.filterInstallablePackagingSpec(ps) && ps.Partition() == "system"
 }