Add protobuf kotlin

Author: SessionHero01

gradle/libs.versions.toml

@@ -10,8 +10,9 @@ androidx-test-rules = { module = "androidx.test:rules", version = "1.7.0" }
 androidx-test-ext = { module = "androidx.test.ext:junit", version = "1.3.0" }
 androidx-annotations = { module = "androidx.annotation:annotation", version = "1.9.1" }
 kotlinx-serialization-core = { module = "org.jetbrains.kotlinx:kotlinx-serialization-core", version = "1.9.0" }
-protoc = { module = "com.google.protobuf:protoc", version = "4.33.1" }
-protobuf-java = { module = "com.google.protobuf:protobuf-java", version.ref = "protobufVersion" }
+protoc-core = { module = "com.google.protobuf:protoc", version = "4.33.1" }
+protoc-kotlin = { module = "com.google.protobuf:protoc-gen-kotlin", version = "1.28.0" }
+protobuf-kotlin = { module = "com.google.protobuf:protobuf-kotlin", version.ref = "protobufVersion" }
 
 [plugins]
 android-library = { id = "com.android.library", version.ref = "agp" }

library/build.gradle.kts

@@ -1,3 +1,4 @@
+import com.google.protobuf.gradle.id
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 plugins {
@@ -80,7 +81,13 @@ kotlin {
 
 protobuf {
     protoc {
-        artifact = libs.protoc.get().toString()
+        artifact = libs.protoc.core.get().toString()
+    }
+
+    plugins {
+        id("kotlin") {
+            artifact = libs.protoc.kotlin.get().toString()
+        }
     }
 
     plugins {
@@ -140,7 +147,7 @@ dependencies {
     implementation(libs.androidx.annotations)
     implementation(libs.kotlinx.serialization.core)
 
-    compileOnly(libs.protobuf.java)
+    api(libs.protobuf.kotlin)
 
     protobuf(files("../libsession-util/proto/SessionProtos.proto"))
 }