Add layout lib system properties so that parcel tests run.

This is for the parcel part of deprecated android extensions.
So this will be removed soon, but it is still there and the
tests should run.

plugins/android-extensions/android-extensions-compiler/build.gradle.kts

@@ -8,6 +8,8 @@ plugins {
 
 val robolectricClasspath by configurations.creating
 val androidExtensionsRuntimeForTests by configurations.creating
+val layoutLib by configurations.creating
+val layoutLibApi by configurations.creating
 
 dependencies {
     testApi(intellijCore())
@@ -42,6 +44,9 @@ dependencies {
     embedded(project(":kotlin-android-extensions-runtime")) { isTransitive = false }
 
     androidExtensionsRuntimeForTests(project(":kotlin-android-extensions-runtime"))  { isTransitive = false }
+
+    layoutLib("org.jetbrains.intellij.deps.android.tools:layoutlib:26.5.0") { isTransitive = false }
+    layoutLibApi("com.android.tools.layoutlib:layoutlib-api:26.5.0") { isTransitive = false }
 }
 
 optInToExperimentalCompilerApi()
@@ -74,8 +79,13 @@ projectTest {
         robolectricClasspath.asPath
     }
 
+    val layoutLibConf: FileCollection = layoutLib
+    val layoutLibApiConf: FileCollection = layoutLibApi
+
     doFirst {
         systemProperty("androidExtensionsRuntime.classpath", androidExtensionsRuntimeProvider.get())
         systemProperty("robolectric.classpath", robolectricClasspathProvider.get())
+        systemProperty("layoutLib.path", layoutLibConf.singleFile.canonicalPath)
+        systemProperty("layoutLibApi.path", layoutLibApiConf.singleFile.canonicalPath)
     }
 }