stub: Add @InlineMe to deprecated gRPC APIs (#8457)

Read more @ https://errorprone.info/docs/inlineme

stub/BUILD.bazel

@@ -8,6 +8,7 @@ java_library(
         "//api",
         "//context",
         "@com_google_code_findbugs_jsr305//jar",
+        "@com_google_errorprone_error_prone_annotations//jar",
         "@com_google_guava_guava//jar",
         "@com_google_j2objc_j2objc_annotations//jar",
     ],

stub/build.gradle

@@ -10,6 +10,7 @@ description = "gRPC: Stub"
 dependencies {
     api project(':grpc-api'),
         libraries.guava
+    implementation libraries.errorprone
     testImplementation libraries.truth,
             project(':grpc-testing')
     signature "org.codehaus.mojo.signature:java17:1.0@signature"

stub/src/main/java/io/grpc/stub/MetadataUtils.java

@@ -18,6 +18,7 @@ package io.grpc.stub;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
+import com.google.errorprone.annotations.InlineMe;
 import io.grpc.CallOptions;
 import io.grpc.Channel;
 import io.grpc.ClientCall;
@@ -47,6 +48,10 @@ public final class MetadataUtils {
    */
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1789")
   @Deprecated
+  @InlineMe(
+      replacement =
+          "stub.withInterceptors(MetadataUtils.newAttachHeadersInterceptor(extraHeaders))",
+      imports = "io.grpc.stub.MetadataUtils")
   public static <T extends AbstractStub<T>> T attachHeaders(T stub, Metadata extraHeaders) {
     return stub.withInterceptors(newAttachHeadersInterceptor(extraHeaders));
   }
@@ -104,6 +109,11 @@ public final class MetadataUtils {
    */
   @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1789")
   @Deprecated
+  @InlineMe(
+      replacement =
+          "stub.withInterceptors(MetadataUtils.newCaptureMetadataInterceptor(headersCapture,"
+              + " trailersCapture))",
+      imports = "io.grpc.stub.MetadataUtils")
   public static <T extends AbstractStub<T>> T captureMetadata(
       T stub,
       AtomicReference<Metadata> headersCapture,