Move noDocs property to SupportLibraryExtension

Test: ./gradlew clean createArchive
Change-Id: Id26b6b9d4f9c52769ffa6f59d1c78df268a8b331
diff --git a/room/compiler/build.gradle b/room/compiler/build.gradle
index 2b35032..57ff63f 100644
--- a/room/compiler/build.gradle
+++ b/room/compiler/build.gradle
@@ -27,7 +27,6 @@
     test.java.srcDirs += 'src/tests/kotlin'
     main.java.srcDirs += antlrOut
 }
-project.ext.noDocs = true
 
 // Temporary hack to stop AS to adding two guavas into test's classpath
 configurations.all {
@@ -80,6 +79,7 @@
 supportLibrary {
     name = "Android Room Compiler"
     publish = true
+    generateDocs = false
     mavenVersion = LibraryVersions.ROOM
     mavenGroup = LibraryGroups.ROOM
     inceptionYear = "2017"