Keep android tests in libs/test folder

To avoid 'com.android.dex.DexException: Too many classes in --main-dex-list, main dex capacity exceeded

compiler/android-tests/android-module/build.gradle

@@ -67,9 +67,9 @@ android {
 task jarTestFolders() {
     println "Jar folders..."
     new File("${projectDir}/libs/").listFiles().each { File file ->
-        if (file.isDirectory()) {
+        if (file.isDirectory() && !file.name.equals("test")) {
             println "Jar '${file.name}' folder..."
-            ant.jar(basedir: "libs/${file.name}/", destfile: "libs/" +  file.name  + ".jar")
+            ant.jar(basedir: "libs/${file.name}/", destfile: "libs/test/" +  file.name  + ".jar")
         }
     }
 }
@@ -83,4 +83,5 @@ dependencies {
     androidTestImplementation 'junit:junit:4.12'
     implementation 'com.android.support:multidex:1.0.3'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestCompile fileTree(dir: 'libs/test', include: ['*.jar'])
 }