use absolute paths in gradle script

Author: Mihail Slavchev

build/project-template-gradle/build.gradle

@@ -158,7 +158,7 @@ dependencies {
     compile "com.android.support:appcompat-v7:$suppotVer"
 
     // take all jars within the libs dir
-	compile fileTree(dir: "libs", include: ["**/*.jar"])
+	compile fileTree(dir: "$projectDir/libs", include: ["**/*.jar"])
 
 	// take all jars within the node_modules dir
 	compile fileTree(dir: nodeModulesDir, include: ["**/platforms/android/**/*.jar"], exclude: '**/.bin/**')