Mark libscrypt_static as vendor_available

This commit marks libscrypt_static as vendor_available so that vendor
modules can depend on libscrypt_static.

Bug: 65425184
Test: BOARD_VNDK_VERSION=current mm -j8

Change-Id: I06bcc80cb71c60d75bf15873632042e72bf3f57c
diff --git a/Android.bp b/Android.bp
index f3aa4d0..ef9b8a0 100644
--- a/Android.bp
+++ b/Android.bp
@@ -22,6 +22,7 @@
     shared_libs: ["libcrypto"],
     sdk_version: "9",
     host_supported: true,
+    vendor_available: true,
 }
 
 cc_test {