add exclude_shared_libs for vendor_available:true libs

Adding a mechanism to conditionally exclude some shared library
dependencies when a lib is built for vendors.

Without this, some libraries cannot be earily marked as vendor_available
if they are depending on shared libs can shouldn't be marked as
vendor_available.

By using exclude_shared_libs with exclude_srcs (or __ANDROID_VNDK__
macro), we can eliminate the unnecessary dependency for vendors.

Bug: 62471389
Test: build

Change-Id: If94277b45c3769223cea371d0028e75277640356
diff --git a/cc/util.go b/cc/util.go
index d9cd6f7..eeb64eb 100644
--- a/cc/util.go
+++ b/cc/util.go
@@ -66,6 +66,16 @@
 	return
 }
 
+func removeListFromList(list []string, filter_out []string) (result []string) {
+	result = make([]string, 0, len(list))
+	for _, l := range list {
+		if !inList(l, filter_out) {
+			result = append(result, l)
+		}
+	}
+	return
+}
+
 func removeFromList(s string, list []string) (bool, []string) {
 	i := indexList(s, list)
 	if i != -1 {