Add Java helper code for establishing binder transport connection (#26862)

These Java code will be invoked by binder transport C++ implementation
through JNI to establish the connection between client and server.

The code is locally tested with other pending changes to make sure it
works correctly.

For now we only make sure it builds in CI. We will port proper tests
from internal repository later.

A new local repository is created for the Android-only Java code because
1. The analysis of its BUILD will fail without Android SDK configured
2. We want to prevent clang-tidy (and maybe other scripts)'s automatic
expansion of '...' to include it as they typically don't have Android
SDK installed

1 files changed, 10 insertions, 0 deletions

diff --git a/WORKSPACE b/WORKSPACE
index 9f7b7e5e51..2288b605a4 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -91,6 +91,16 @@ android_ndk_repository(
     # https://github.com/bazelbuild/bazel/issues/13421
 )
 
+# Prevents bazel's '...' expansion from including the following folder.
+# This is required because the BUILD file in the following folder
+# will trigger bazel failure when Android SDK is not configured.
+# The targets in the following folder need to be included in APK and will
+# be invoked by binder transport implementation through JNI.
+local_repository(
+    name = "binder_transport_android_helper",
+    path = "./src/core/ext/transport/binder/java",
+)
+
 # Create msan toolchain configuration for remote execution.
 rbe_autoconfig(
     name = "rbe_msan",