Merge changes from topic "installclean-symbols-mainline-prod" into mainline-prod

* changes:
  Clean symbols directory during installclean
  Ignore cc.Module.HideFromMake when producing flattened apex Android.mk entries
diff --git a/apex/androidmk.go b/apex/androidmk.go
index 9f78857..66f4dc8 100644
--- a/apex/androidmk.go
+++ b/apex/androidmk.go
@@ -79,10 +79,6 @@
 	}
 
 	for _, fi := range a.filesInfo {
-		if ccMod, ok := fi.module.(*cc.Module); ok && ccMod.Properties.HideFromMake {
-			continue
-		}
-
 		linkToSystemLib := a.linkToSystemLib && fi.transitiveDep && fi.AvailableToPlatform()
 
 		var moduleName string
diff --git a/ui/build/cleanbuild.go b/ui/build/cleanbuild.go
index 0bcdccb..594aeff 100644
--- a/ui/build/cleanbuild.go
+++ b/ui/build/cleanbuild.go
@@ -131,7 +131,8 @@
 		productOut("installer"),
 		productOut("odm"),
 		productOut("sysloader"),
-		productOut("testcases"))
+		productOut("testcases"),
+		productOut("symbols"))
 }
 
 // Since products and build variants (unfortunately) shared the same