Convert GMavenVersionChecker to Kotlin.

The last groovy class (except for build scripts)!!!

Test: ./gradlew createDiffArchive --info
Change-Id: Ifc596ef95257ef680843b56452ddb64b63cce89f
diff --git a/buildSrc/init.gradle b/buildSrc/init.gradle
index cef2bed..4914cee 100644
--- a/buildSrc/init.gradle
+++ b/buildSrc/init.gradle
@@ -16,7 +16,6 @@
 
 
 import android.support.DiffAndDocs
-import android.support.SupportConfig
 import android.support.gmaven.GMavenVersionChecker
 import com.android.build.gradle.internal.coverage.JacocoReportTask
 import com.android.build.gradle.internal.tasks.DeviceProviderInstrumentTestTask
@@ -31,7 +30,7 @@
 }
 def init = new Properties()
 ext.init = init
-rootProject.ext.versionChecker = new GMavenVersionChecker(rootProject)
+rootProject.ext.versionChecker = new GMavenVersionChecker(rootProject.logger)
 ext.runningInBuildServer = System.env.DIST_DIR != null && System.env.OUT_DIR != null
 
 apply from: "${supportRoot}/buildSrc/dependencies.gradle"