Generate VNDK snapshot with Soong except configs

This is the first commit to generate VNDK snapshot with Soong: .so
files, some txt files, and notice files are captured with Soong. As
ld.config.txt is currently in Android.mk and will be deprecated soon,
configs files (and zipping all of artifacts) are still handled with
Makefile.

Bug: 131564934
Test: 1) DIST_DIR=out/dist development/vndk/snapshot/build.sh
Test: 2) try installing vndk snapshot with:
     development/vndk/snapshot/update.py

Change-Id: I8629e1e25bfc461fd495565bb4872c9af176cf92
diff --git a/android/util.go b/android/util.go
index f9dce6f..f7a3437 100644
--- a/android/util.go
+++ b/android/util.go
@@ -52,6 +52,31 @@
 	return string(ret)
 }
 
+func JoinWithSuffix(strs []string, suffix string, separator string) string {
+	if len(strs) == 0 {
+		return ""
+	}
+
+	if len(strs) == 1 {
+		return strs[0] + suffix
+	}
+
+	n := len(" ") * (len(strs) - 1)
+	for _, s := range strs {
+		n += len(suffix) + len(s)
+	}
+
+	ret := make([]byte, 0, n)
+	for i, s := range strs {
+		if i != 0 {
+			ret = append(ret, separator...)
+		}
+		ret = append(ret, s...)
+		ret = append(ret, suffix...)
+	}
+	return string(ret)
+}
+
 func sortedKeys(m map[string][]string) []string {
 	s := make([]string, 0, len(m))
 	for k := range m {