Add missing dependency on protoc

Change-Id: I696f55cb57b3236ebf4e3f7139f0e8354279fe4a
diff --git a/d8_r8/commonBuildSrc/src/main/kotlin/DependenciesPlugin.kt b/d8_r8/commonBuildSrc/src/main/kotlin/DependenciesPlugin.kt
index 867616c..48186d2 100644
--- a/d8_r8/commonBuildSrc/src/main/kotlin/DependenciesPlugin.kt
+++ b/d8_r8/commonBuildSrc/src/main/kotlin/DependenciesPlugin.kt
@@ -683,6 +683,10 @@
     Paths.get("third_party", "proguardsettings").toFile(),
     Paths.get("third_party", "proguardsettings.tar.gz.sha1").toFile(),
     DependencyType.X20)
+  val protoc = ThirdPartyDependency(
+    "protoc",
+    Paths.get("third_party", "protoc").toFile(),
+    Paths.get("third_party", "protoc.tar.gz.sha1").toFile())
   val protoRuntimeEdition2023 = ThirdPartyDependency(
     "protoRuntimeEdition2023",
     Paths.get("third_party", "proto", "runtime", "edition2023").toFile(),