fix shading

Author: laurit

testing/proto-shaded-for-testing/build.gradle.kts

@@ -12,6 +12,11 @@ tasks {
   shadowJar {
     relocate("io.opentelemetry.proto", "io.opentelemetry.testing.internal.proto")
     relocate("com.google.protobuf", "io.opentelemetry.testing.internal.protobuf")
+    relocate("com.google.gson", "io.opentelemetry.testing.internal.gson")
+    relocate("com.google.common", "io.opentelemetry.testing.internal.guava")
+
+    enableAutoRelocation = true
+    relocationPrefix = "io.opentelemetry.testing.internal"
   }
 
   val extractShadowJar by registering(Copy::class) {