Allow uninstallable prebuilt_etc to be packaged

Till now, prebuilt_etc has to be installable to be packaged. With this
commit, packaging modules like filesystem now can include uninstallable
prebuilt_etc. This can help when prebuilt_etc can conflict with other
partitions e.g. system.

Bug: 179340780
Test: build filesystem with uninstallable prebuilt_etc
Change-Id: Id981fe7ce41f1189eb0f85f2d1677d973004423c
diff --git a/etc/prebuilt_etc.go b/etc/prebuilt_etc.go
index 57563eb..e15324b 100644
--- a/etc/prebuilt_etc.go
+++ b/etc/prebuilt_etc.go
@@ -282,11 +282,14 @@
 		Input:  p.sourceFilePath,
 	})
 
-	if p.Installable() {
-		installPath := ctx.InstallFile(p.installDirPath, p.outputFilePath.Base(), p.outputFilePath)
-		for _, sl := range p.properties.Symlinks {
-			ctx.InstallSymlink(p.installDirPath, sl, installPath)
-		}
+	if !p.Installable() {
+		p.SkipInstall()
+	}
+
+	// Call InstallFile even when uninstallable to make the module included in the package
+	installPath := ctx.InstallFile(p.installDirPath, p.outputFilePath.Base(), p.outputFilePath)
+	for _, sl := range p.properties.Symlinks {
+		ctx.InstallSymlink(p.installDirPath, sl, installPath)
 	}
 }