Move GatherPackagingSpecs out of CopyDepsToZip

This gives a PackageModule a chance to filter/customize the contents of
resulting package.

Bug: 225121718
Test: m (no changes)
Change-Id: I45505e8234dff42201dc40d4f038e7b08eea89f0
diff --git a/snapshot/host_snapshot.go b/snapshot/host_snapshot.go
index 09a382e..e1d6154 100644
--- a/snapshot/host_snapshot.go
+++ b/snapshot/host_snapshot.go
@@ -145,7 +145,7 @@
 
 	f.installDir = android.PathForModuleInstall(ctx)
 
-	f.CopyDepsToZip(ctx, depsZipFile)
+	f.CopyDepsToZip(ctx, f.GatherPackagingSpecs(ctx), depsZipFile)
 
 	builder := android.NewRuleBuilder(pctx, ctx)
 	builder.Command().