Update Android Gradle plugin to 3.2.0

Author: friederbluemle

app/proguard-rules.pro

@@ -1,14 +1,10 @@
 # Add project specific ProGuard rules here.
-# By default, the flags in this file are appended to flags specified
-# in /Users/mertsimsek/Library/Android/sdk/tools/proguard/proguard-android.txt
-# You can edit the include path and order by changing the proguardFiles
-# directive in build.gradle.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
 #
 # For more details, see
 #   http://developer.android.com/guide/developing/tools/proguard.html
 
-# Add any project specific keep options here:
-
 # If your project uses WebView with JS, uncomment the following
 # and specify the fully qualified class name to the JavaScript interface
 # class:

build.gradle

@@ -1,23 +1,17 @@
-// Top-level build file where you can add configuration options common to all sub-projects/modules.
-
 buildscript {
-
     repositories {
-        maven { url 'https://maven.google.com' }
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.0'
-
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
+        classpath 'com.android.tools.build:gradle:3.2.0'
     }
 }
 
 allprojects {
     repositories {
+        google()
         jcenter()
-        maven { url 'https://maven.google.com' }
     }
 }