Add support for kotlin plugins

Use the already existing hooks used by the compose
compiler plugin to support kotlin plugins bundled
alongside the compiler such as kotlin-serialize-compiler

Test: m, sample app with kotlin-serialize-compiler
Change-Id: I4d5fa6cd42acfc90ef437222e9e07f61c259d565

java/plugin.go

@@ -24,6 +24,7 @@ func init() {
 
 func registerJavaPluginBuildComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("java_plugin", PluginFactory)
+	ctx.RegisterModuleType("kotlin_plugin", KotlinPluginFactory)
 }
 
 func PluginFactory() android.Module {
@@ -37,6 +38,16 @@ func PluginFactory() android.Module {
 	return module
 }
 
+func KotlinPluginFactory() android.Module {
+	module := &KotlinPlugin{}
+
+	module.addHostProperties()
+
+	InitJavaModule(module, android.HostSupported)
+
+	return module
+}
+
 // Plugin describes a java_plugin module, a host java library that will be used by javac as an annotation processor.
 type Plugin struct {
 	Library
@@ -53,3 +64,8 @@ type PluginProperties struct {
 	// parallelism and cause more recompilation for modules that depend on modules that use this plugin.
 	Generates_api *bool
 }
+
+// Plugin describes a kotlin_plugin module, a host java/kotlin library that will be used by kotlinc as a compiler plugin.
+type KotlinPlugin struct {
+	Library
+}