Upgrade to protobuf-gradle-plugin 0.8.16

This plugin pulls in fixes for gradle configuration caching.
https://github.com/google/protobuf-gradle-plugin/releases

Test: ./gradlew tasks
Change-Id: I3fb4dcf8c4848a83c0a6fe69f620c4d660b825a3
diff --git a/androidx-plugin/gradle-plugin/build.gradle b/androidx-plugin/gradle-plugin/build.gradle
index 7f6bef7..982e077 100644
--- a/androidx-plugin/gradle-plugin/build.gradle
+++ b/androidx-plugin/gradle-plugin/build.gradle
@@ -26,7 +26,7 @@
 
     // Not really sure about these:
     implementation("androidx.benchmark:benchmark-gradle-plugin:1.0.0")
-    implementation("com.google.protobuf:protobuf-gradle-plugin:0.8.13")
+    implementation(libs.protobufGradlePlugin)
     implementation(libs.shadow)
     implementation(libs.wireGradlePlugin)
 }
diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index 711d182..deed960 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -68,7 +68,7 @@
     cacheableImplementation(gradleApi())
     cacheableApi(libs.dokkaGradlePlugin)
     // needed by inspection plugin
-    cacheableImplementation("com.google.protobuf:protobuf-gradle-plugin:0.8.13")
+    cacheableImplementation(libs.protobufGradlePlugin)
     cacheableImplementation(libs.wireGradlePlugin)
     cacheableImplementation(libs.shadow)
     // dependencies that aren't used by buildSrc directly but that we resolve here so that the
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index c7c3f9f..60a1d2b 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -119,6 +119,7 @@
 playServicesBase = { module = "com.google.android.gms:play-services-base", version = "17.0.0" }
 protobuf = { module = "com.google.protobuf:protobuf-java", version = "3.4.0" }
 protobufCompiler = { module = "com.google.protobuf:protoc", version = "3.10.0" }
+protobufGradlePlugin = { module = "com.google.protobuf:protobuf-gradle-plugin", version = "0.8.16" }
 protobufLite = { module = "com.google.protobuf:protobuf-javalite", version = "3.4.0" }
 reactiveStreams = { module = "org.reactivestreams:reactive-streams", version = "1.0.0" }
 retrofit = { module = "com.squareup.retrofit2:retrofit", version = "2.7.2" }
diff --git a/inspection/inspection-gradle-plugin/build.gradle b/inspection/inspection-gradle-plugin/build.gradle
index 11c4c81..9e6ded91 100644
--- a/inspection/inspection-gradle-plugin/build.gradle
+++ b/inspection/inspection-gradle-plugin/build.gradle
@@ -35,7 +35,7 @@
     implementation(gradleApi())
     implementation(AGP_LATEST)
     implementation(KOTLIN_STDLIB)
-    implementation("gradle.plugin.com.google.protobuf:protobuf-gradle-plugin:0.8.13")
+    implementation(libs.protobufGradlePlugin)
     implementation(libs.shadow)
 
     testImplementation(project(":internal-testutils-gradle-plugin"))