Add protobuf-kotlin library.

Minor driveby: Fixed importMaven script in the README per the error received from the deprecated script.

Related to: r.android.com/2295258

Change-Id: I5a0b8fbcd7cab52d8d343b06c59db74d0c61acb9
diff --git a/gradle/README.md b/gradle/README.md
index 232393b..e945e4e 100644
--- a/gradle/README.md
+++ b/gradle/README.md
@@ -4,7 +4,7 @@
 
 ## libs.versions.toml
 
-Keeps track of library and plugin dependencies used by androidx. Adding or updating a library there requires running `./development/importMaven/import_maven_artifacts.py -n myartifact:here:1.0.0`
+Keeps track of library and plugin dependencies used by androidx. Adding or updating a library there requires running `./development/importMaven/importMaven.sh myartifact:here:1.0.0`
 
 ## verification-keyring.keys
 
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index a977599..25b345e 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -208,6 +208,7 @@
 protobufCompiler = { module = "com.google.protobuf:protoc", version.ref = "protobuf" }
 protobufGradlePluginz = { module = "com.google.protobuf:protobuf-gradle-plugin", version = "0.9.0" }
 protobufLite = { module = "com.google.protobuf:protobuf-javalite", version.ref = "protobuf" }
+protobufKotlin = { module = "com.google.protobuf:protobuf-kotlin", version.ref = "protobuf" }
 reactiveStreams = { module = "org.reactivestreams:reactive-streams", version = "1.0.0" }
 retrofit = { module = "com.squareup.retrofit2:retrofit", version.ref = "retrofit" }
 retrofitConverterWire = { module = "com.squareup.retrofit2:converter-wire", version.ref = "retrofit" }