project: Update gradle files

These are automatic changes made by Android Studio 3.0.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/build.gradle

@@ -1,26 +1,26 @@
 apply plugin: 'com.android.application'
 
 android {
-    buildToolsVersion "26.0.0"
+    buildToolsVersion "27.0.0"
     buildTypes {
         release {
             minifyEnabled false
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
-    compileSdkVersion 26
+    compileSdkVersion 27
     dataBinding {
         enabled true
     }
     defaultConfig {
         applicationId "com.wireguard.android"
         minSdkVersion 21
-        targetSdkVersion 26
+        targetSdkVersion 27
         versionCode 100
         versionName "0.1.0"
     }
 }
 
 dependencies {
-    compile fileTree(dir: 'libs', include: ['*.jar'])
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
 }

build.gradle

@@ -1,14 +1,16 @@
 allprojects {
     repositories {
+        google()
         jcenter()
     }
 }
 
 buildscript {
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.3'
+        classpath 'com.android.tools.build:gradle:3.0.0'
     }
     repositories {
+        google()
         jcenter()
     }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists