Fixes the resources in the app/* not found in development mode

ResourceLocator should use `BuildSettings.GRAILS_APP_PATH` instead of `GrailsResourceUtils.GRAILS_APP_DIR`

Closes gh-1251

Author: rainboyan

grace-bootstrap/src/main/groovy/org/grails/io/support/ResourceLocator.java

@@ -29,6 +29,7 @@
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
 
+import grails.util.BuildSettings;
 import grails.util.Environment;
 
 /**
@@ -84,22 +85,14 @@ public void setSearchLocations(Collection<String> searchLocations) {
     private void initializeForSearchLocation(String searchLocation) {
         String searchLocationPlusSlash = searchLocation.endsWith("/") ? searchLocation : searchLocation + FILE_SEPARATOR;
         try {
-            File[] directories = new File(searchLocationPlusSlash + GrailsResourceUtils.GRAILS_APP_DIR)
+            File[] directories = new File(searchLocationPlusSlash + BuildSettings.GRAILS_APP_PATH)
                     .listFiles(file -> file.isDirectory() && !file.isHidden());
 
             if (directories != null) {
                 for (File directory : directories) {
                     this.classSearchDirectories.add(directory.getCanonicalPath());
                 }
             }
-            File[] appDirectories = new File(searchLocationPlusSlash + "app")
-                    .listFiles(file -> file.isDirectory() && !file.isHidden());
-
-            if (appDirectories != null) {
-                for (File directory : appDirectories) {
-                    this.classSearchDirectories.add(directory.getCanonicalPath());
-                }
-            }
         }
         catch (IOException ignored) {
         }

grace-core/src/main/groovy/org/grails/core/io/DefaultResourceLocator.java

@@ -33,9 +33,9 @@
 import grails.plugins.GrailsPlugin;
 import grails.plugins.GrailsPluginManager;
 import grails.plugins.PluginManagerAware;
+import grails.util.BuildSettings;
 import grails.util.Environment;
 
-import org.grails.io.support.GrailsResourceUtils;
 import org.grails.plugins.BinaryGrailsPlugin;
 
 /**
@@ -93,7 +93,7 @@ public void setSearchLocations(Collection<String> searchLocations) {
     private void initializeForSearchLocation(String searchLocation) {
         String searchLocationPlusSlash = searchLocation.endsWith("/") ? searchLocation : searchLocation + FILE_SEPARATOR;
         try {
-            File[] directories = new File(searchLocationPlusSlash + GrailsResourceUtils.GRAILS_APP_DIR)
+            File[] directories = new File(searchLocationPlusSlash + BuildSettings.GRAILS_APP_PATH)
                     .listFiles(file -> file.isDirectory() && !file.isHidden());
 
             if (directories != null) {