Version liblog LL-NDK library

The system version of liblog has been versioned.  Do the same for
LL-NDK verison as well.

Test: Build and examine the dynamic symbols.
Change-Id: Ie63cc845c891d9372fb1990e713b3fe4f0f2f723

liblog/Android.bp

@@ -139,6 +139,5 @@ ndk_library {
 llndk_library {
     name: "liblog",
     symbol_file: "liblog.map.txt",
-    unversioned: true,
     export_include_dirs: ["include_vndk"],
 }