Separate out target defaults in the GN build config.

build/config/ios/rules.gni

Index: build/config/ios/rules.gni
diff --git a/build/config/ios/rules.gni b/build/config/ios/rules.gni
index aec0de5b8fa322d77b856fa4906ba88939bc995c..6edec87e9401f6b9c68b4d573cfc1d60eaff36a0 100644
--- a/build/config/ios/rules.gni
+++ b/build/config/ios/rules.gni
@@ -438,6 +438,10 @@ template("ios_app_bundle") {
   }
 }
 
+set_defaults("ios_app_bundle") {
+  configs = default_executable_configs
+}
+
 # Template to build an application extension bundle for iOS.
 #
 # This should be used instead of "executable" built-in target type on iOS.
@@ -490,6 +494,10 @@ template("ios_appex_bundle") {
   }
 }
 
+set_defaults("ios_appex_bundle") {
+  configs = default_executable_configs
+}
+
 # Compile a xib or storyboard file and add it to a bundle_data so that it is
 # available at runtime in the bundle.
 #
@@ -784,3 +792,7 @@ template("ios_framework_bundle") {
     }
   }
 }
+
+set_defaults("ios_framework_bundle") {
+  configs = default_shared_library_configs
+}