move classes out of native_loader.cpp

native_loader.cpp is too crowded. Move the classes
NativeLoaderNamespaces and LibraryNamespaces out of native_loader.cpp to
their own source files.

This change does not alter any functionality.

Bug: 130388701
Test: m, presubmit tests
Change-Id: Ibc61ec0dc6727af7cac865b1971ebf1befac6855
diff --git a/libnativeloader/Android.bp b/libnativeloader/Android.bp
index 66cb49f..4d65b50 100644
--- a/libnativeloader/Android.bp
+++ b/libnativeloader/Android.bp
@@ -17,7 +17,9 @@
     name: "libnativeloader",
     defaults: ["libnativeloader-defaults"],
     host_supported: true,
-    srcs: ["native_loader.cpp"],
+    srcs: [
+        "native_loader.cpp",
+    ],
     shared_libs: [
         "libnativehelper",
         "liblog",
@@ -26,6 +28,9 @@
     ],
     target: {
         android: {
+            srcs: [
+                "library_namespaces.cpp",
+            ],
             shared_libs: [
                 "libdl_android",
             ],