Build Improvements (#9855)

* Made dependency on build.gradle in protobuf tasks relative so as to make downstream tasks cacheable

* Made transformer cacheable

* Add property name to path to root build.gradle

Co-authored-by: Nelson Osacky <nelson@osacky.com>

build.gradle

@@ -70,7 +70,9 @@ subprojects {
                     all().each { task ->
                         // Recompile protos when build.gradle has been changed, because
                         // it's possible the version of protoc has been changed.
-                        task.inputs.file "${rootProject.projectDir}/build.gradle"
+                        task.inputs.file("${rootProject.projectDir}/build.gradle")
+                          .withPathSensitivity(PathSensitivity.RELATIVE)
+                          .withPropertyName('root build.gradle')
                         if (isAndroid) {
                             task.builtins {
                                 java { option 'lite' }

netty/shaded/build.gradle

@@ -1,4 +1,5 @@
 import com.github.jengelman.gradle.plugins.shadow.transformers.Transformer
+import com.github.jengelman.gradle.plugins.shadow.transformers.CacheableTransformer
 import com.github.jengelman.gradle.plugins.shadow.transformers.TransformerContext
 import org.gradle.api.file.FileTreeElement
 import shadow.org.apache.tools.zip.ZipOutputStream
@@ -140,6 +141,7 @@ tasks.named("test").configure {
  * A Transformer which updates the Netty JAR META-INF/ resources to accurately
  * reference shaded class names.
  */
+@CacheableTransformer
 class NettyResourceTransformer implements Transformer {
 
     // A map of resource file paths to be modified