fix: clean android build artifacts when using with uglify

Author: sis0k0

Diff for: bin/ns-bundle

@@ -69,7 +69,7 @@ function cleanBuildArtifacts(platform) {
 
             // for nativescript-cli v3.0.1 and below
             // the android build artifacts should be cleaned manually
-            if (version <= 301) {
+            if (shouldUglify() || version <= 301) {
                 gradlewClean().then(resolve).catch(throwError);
             } else {
                 return resolve();
@@ -133,7 +133,7 @@ function webpack(platform) {
             `--config=webpack.config.js`,
             `--progress`,
             `--env.${platform}`,
-            process.env.npm_config_uglify && `--env.uglify`,
+            shouldUglify() && `--env.uglify`,
         ];
 
         spawnChildProcess(...args)
@@ -205,6 +205,10 @@ function spawnChildProcess(command, ...args) {
     });
 }
 
+function shouldUglify() {
+    return process.env.npm_config_uglify;
+}
+
 function throwError(error) {
     console.error(error.message);
     process.exit(error.code || 1);