Add vendor_available:true to libmemunreachable

Bug: 38244611
Test: build sailfish

Merged-In: I5f238377784b3a30308e9e5cb0817c71675edddf
Change-Id: Ieb7fdcae4b96a1e1622ba98a7cfb56a95b798452
(cherry picked from commit 52eaeb48255082ceaafea20dd9339545b6174fb4)
diff --git a/libmemunreachable/Android.bp b/libmemunreachable/Android.bp
index 4662368..1b8830a 100644
--- a/libmemunreachable/Android.bp
+++ b/libmemunreachable/Android.bp
@@ -15,6 +15,7 @@
 
 cc_library_shared {
     name: "libmemunreachable",
+    vendor_available: true,
     defaults: ["libmemunreachable_defaults"],
     srcs: [
         "Allocator.cpp",