RTL support added

Author: enchev

lib/services/android-project-service.ts

@@ -257,14 +257,15 @@ export class AndroidProjectService extends projectServiceBaseLib.PlatformProject
 			if (this.canUseGradle().wait()) {
 				// Validate App_Resources drawable resources accoring to the official docs: https://developer.android.com/guide/topics/resources/providing-resources.html
 				let drawableFilePrefix = "drawable-";
+				let rtlDrawableFilePrefix = "drawable-ldrtl-";
 				let allowedDrawables = ["ldpi", "mdpi", "hdpi", "xhdpi", "xxhdpi", "xxxhdpi", "nodpi", "tvdpi"];
 				let appSourceDirectoryPath = path.join(this.$projectData.projectDir, constants.APP_FOLDER_NAME);
 				let sourceAppResourcesDirectoryPath = path.join(appSourceDirectoryPath, constants.APP_RESOURCES_FOLDER_NAME, this.$devicePlatformsConstants.Android);
 
 				if (this.$fs.exists(sourceAppResourcesDirectoryPath).wait()) {
 					this.$fs.enumerateFilesInDirectorySync(sourceAppResourcesDirectoryPath, (file: string, stat: IFsStats) => {
-						if (stat.isDirectory() && file.indexOf(drawableFilePrefix) !== -1 &&
-							allowedDrawables.indexOf(path.basename(file).replace(drawableFilePrefix, "")) === -1) {
+						if (stat.isDirectory() && (file.indexOf(drawableFilePrefix) !== -1 && allowedDrawables.indexOf(path.basename(file).replace(drawableFilePrefix, "")) === -1) ||
+							(file.indexOf(rtlDrawableFilePrefix) !== -1 && allowedDrawables.indexOf(path.basename(file).replace(rtlDrawableFilePrefix, "")) === -1)) {
 							this.$errors.failWithoutHelp(`Invalid Android drawable resource folder detected: ${file}. Please check your ${constants.APP_RESOURCES_FOLDER_NAME} folder.`);
 							return false;
 						}