Simplify the thunk targets since we don't support apps as components

examples/surfaces_app/BUILD.gn

Index: examples/surfaces_app/BUILD.gn
diff --git a/examples/surfaces_app/BUILD.gn b/examples/surfaces_app/BUILD.gn
index 606e37830ee49b082c08ee4b66f5a650c7104f8b..000500da0930f0b7a4a55f29958eb8bbf32070ee 100644
--- a/examples/surfaces_app/BUILD.gn
+++ b/examples/surfaces_app/BUILD.gn
@@ -31,7 +31,6 @@ mojo_native_application("parent_app") {
     "//mojo/converters/geometry",
     "//mojo/converters/surfaces",
     "//mojo/environment:chromium",
-    "//mojo/public/c/system:for_shared_library",
     "//mojo/public/cpp/system",
     "//mojo/services/public/interfaces/geometry",
     "//mojo/services/public/interfaces/gpu",
@@ -62,7 +61,6 @@ mojo_native_application("child_app") {
     "//mojo/converters/geometry",
     "//mojo/converters/surfaces",
     "//mojo/environment:chromium",
-    "//mojo/public/c/system:for_shared_library",
     "//mojo/public/cpp/bindings",
     "//mojo/services/public/interfaces/geometry",
     "//mojo/services/public/interfaces/surfaces",
@@ -96,11 +94,10 @@ mojo_native_application("child_gl_app") {
     "//mojo/converters/geometry",
     "//mojo/converters/surfaces",
     "//mojo/environment:chromium",
-    "//mojo/public/c/system:for_shared_library",
+    "//mojo/public/c/gles2",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/environment",
     "//mojo/public/cpp/system",
-    "//mojo/public/gles2:for_shared_library",
     "//mojo/services/public/interfaces/geometry",
     "//mojo/services/public/interfaces/gpu",
     "//mojo/services/public/interfaces/surfaces",