Fixed unresolved dependency by JCenter

Problem:
* What went wrong:
A problem occurred configuring root project 'TapTargetView'.
> Could not resolve all artifacts for configuration ':classpath'.
   > Could not find aapt2-proto.jar (com.android.tools.build:aapt2-proto:0.3.1).
     Searched in the following locations:
         https://jcenter.bintray.com/com/android/tools/build/aapt2-proto/0.3.1/aapt2-proto-0.3.1.jar

Changing google to the first source for dependencies resolves this issue

build.gradle

@@ -1,7 +1,7 @@
 buildscript {
     repositories {
-        jcenter()
         google()
+        jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.2.0'