Add correct rpath for dawn samples on linux when using gn build

Dawn Samples missing correct rpath settings on linux platform in
BUILD.gn. This failed program to find .so like libdawn_native on linux.

BUILD.gn

@@ -134,6 +134,20 @@ config("libdawn_public") {
   ]
 }
 
+# Executable needs an rpath to find our shared libraries on OSX and Linux
+config("dawn_shared_library_public") {
+  if (is_mac) {
+    ldflags = [
+      "-rpath",
+      "@executable_path/",
+    ]
+  }
+
+  if (is_linux) {
+    configs = [ "//build/config/gcc:rpath_for_built_shared_libraries" ]
+  }
+}
+
 config("dawn_internal") {
   include_dirs = [ "src" ]
 
@@ -158,23 +172,16 @@ config("dawn_internal") {
     defines += [ "DAWN_ENABLE_BACKEND_VULKAN" ]
   }
 
-  configs = [ ":libdawn_public" ]
+  configs = [
+    ":libdawn_public",
+    ":dawn_shared_library_public",
+  ]
 
   # Only internal Dawn targets can use this config, this means only targets in
   # this BUILD.gn file.
   visibility = [ ":*" ]
 }
 
-# Executable needs an rpath to find our shared libraries on OSX
-config("dawn_shared_library_public") {
-  if (is_mac) {
-    ldflags = [
-      "-rpath",
-      "@executable_path/",
-    ]
-  }
-}
-
 static_library("dawn_common") {
   sources = [
     "src/common/Assert.cpp",
@@ -253,7 +260,6 @@ shared_library("libdawn") {
       "-install_name",
       "@rpath/${target_name}.dylib",
     ]
-    public_configs = [ ":dawn_shared_library_public" ]
   }
 }
 
@@ -601,7 +607,6 @@ shared_library("libdawn_native") {
       "-install_name",
       "@rpath/${target_name}.dylib",
     ]
-    public_configs += [ ":dawn_shared_library_public" ]
   }
 }
 
@@ -655,7 +660,6 @@ shared_library("libdawn_wire") {
       "-install_name",
       "@rpath/${target_name}.dylib",
     ]
-    public_configs += [ ":dawn_shared_library_public" ]
   }
 }
 
@@ -732,10 +736,6 @@ dawn_generator("mock_dawn_gen") {
 test("dawn_unittests") {
   configs += [ ":dawn_internal" ]
 
-  if (is_linux) {
-    configs += [ "//build/config/gcc:rpath_for_built_shared_libraries" ]
-  }
-
   deps = [
     ":dawn_common",
     ":dawn_headers",
@@ -788,10 +788,6 @@ test("dawn_unittests") {
 test("dawn_end2end_tests") {
   configs += [ ":dawn_internal" ]
 
-  if (is_linux) {
-    configs += [ "//build/config/gcc:rpath_for_built_shared_libraries" ]
-  }
-
   deps = [
     ":dawn_common",
     ":dawn_utils",