Merge "Add some overview docs for classloader-namespace."

static constexpr const char* kRuntimeNamespaceName = "runtime";

// classloader-namespace is a linker namespace that is created for the loaded

// app. To be specific, it is created for the app classloader. When

// System.load() is called from a Java class that is loaded from the

// classloader, the classloader-namespace namespace associated with that

// classloader is selected for dlopen. The namespace is configured so that its

// search path is set to the app-local JNI directory and it is linked to the

// default namespace with the names of libs listed in the public.libraries.txt.

// This way an app can only load its own JNI libraries along with the public libs.

static constexpr const char* kClassloaderNamespaceName = "classloader-namespace";

// Same thing for vendor APKs.

static constexpr const char* kVendorClassloaderNamespaceName = "vendor-classloader-namespace";

// (http://b/27588281) This is a workaround for apps using custom classloaders and calling