add nopreload option in public.libraries.txt

A lib with 'nopreload' option in public.libraries.txt is not preloaded
during zygote. This is useful for seldom used public libraries; they
don't contribute to the zygote startup time and only affect the apps
that they are used.

Bug: 132911956
Test: libnativeloader_test
Change-Id: I6f97c90e6721aec7f2f96c8fc7b963b34f8edd3e
diff --git a/libnativeloader/library_namespaces.cpp b/libnativeloader/library_namespaces.cpp
index 7f5768c..9a33b55 100644
--- a/libnativeloader/library_namespaces.cpp
+++ b/libnativeloader/library_namespaces.cpp
@@ -124,7 +124,7 @@
   // we might as well end up loading them from /system/lib or /product/lib
   // For now we rely on CTS test to catch things like this but
   // it should probably be addressed in the future.
-  for (const auto& soname : android::base::Split(default_public_libraries(), ":")) {
+  for (const auto& soname : android::base::Split(preloadable_public_libraries(), ":")) {
     LOG_ALWAYS_FATAL_IF(dlopen(soname.c_str(), RTLD_NOW | RTLD_NODELETE) == nullptr,
                         "Error preloading public library %s: %s", soname.c_str(), dlerror());
   }