Implement directed vendor snapshot

Vendors can now generate only needed modules by setting the following
Makefile variables:

- DIRECTED_VENDOR_SNAPSHOT: set to true
- VENDOR_SNAPSHOT_MODULES: list of snapshot candidates

e.g.

DIRECTED_VENDOR_SNAPSHOT := true
VENDOR_SNAPSHOT_MODULES := toybox_vendor sh_vendor libbase libcutils ...

Bug: 157967325
Test: m dist vendor-snapshot after setting those in BoardConfig.mk
Change-Id: I6515a43d9358d94483d7c7fa2b066f9dd457f6aa
diff --git a/cc/snapshot_utils.go b/cc/snapshot_utils.go
index 3e6444b..c50ef45 100644
--- a/cc/snapshot_utils.go
+++ b/cc/snapshot_utils.go
@@ -80,7 +80,7 @@
 	}
 
 	for _, image := range []snapshotImage{vendorSnapshotImageSingleton, recoverySnapshotImageSingleton} {
-		if isSnapshotAware(m, image.isProprietaryPath(ctx.ModuleDir()), apexInfo, image) {
+		if isSnapshotAware(ctx.DeviceConfig(), m, image.isProprietaryPath(ctx.ModuleDir()), apexInfo, image) {
 			return true
 		}
 	}