Enable compose kotlinc plugin when depending on the compose runtime

When a module depends on the compose runtime add a -Xplugin argument
to the kotlinc flags that enables the compose compiler plugin.

Bug: 196351110
Test: TestKotlinCompose
Change-Id: I423a3c4d12df42804a24b672a40a165bc8dd165f
diff --git a/java/kotlin.go b/java/kotlin.go
index 3a6fc0f..e4f1bc1 100644
--- a/java/kotlin.go
+++ b/java/kotlin.go
@@ -81,6 +81,7 @@
 
 	var deps android.Paths
 	deps = append(deps, flags.kotlincClasspath...)
+	deps = append(deps, flags.kotlincDeps...)
 	deps = append(deps, srcJars...)
 	deps = append(deps, commonSrcFiles...)