Rename VulkanViewer to Viewer, take 2.

tools/viewer/android/Window_android.h

Index: tools/viewer/android/Window_android.h
diff --git a/tools/vulkan/android/Window_android.h b/tools/viewer/android/Window_android.h
similarity index 96%
rename from tools/vulkan/android/Window_android.h
rename to tools/viewer/android/Window_android.h
index fa675feb326f3e34b1cb8ed556c8c237983f5efa..6099f8983eaf2845e964afc323cb4c2f6f8bfc98 100644
--- a/tools/vulkan/android/Window_android.h
+++ b/tools/viewer/android/Window_android.h
@@ -11,6 +11,8 @@
 #include "../Window.h"
 #include <android_native_app_glue.h>
 
+namespace sk_app {
+
 enum {
     /**
      * Leave plenty of space between this item and the ones defined in the glue layer
@@ -45,4 +47,6 @@ private:
     int mSampleCount = 0;
 };
 
+}   // namespace sk_app
+
 #endif