Document return values of ABinderRpc_Accessor_delegateAccessor

Also changed the `OK` return value to `STATUS_OK` in the implementation.
The are both anonymous enums with the same value(0), but `STATUS_OK` is
intended to be used as a `binder_status_t`.

Test: na
Bug: 373660469
Change-Id: I66522047356e976bcaa08284b3c83bdb15374ff4
diff --git a/libs/binder/ndk/binder_rpc.cpp b/libs/binder/ndk/binder_rpc.cpp
index 07b8c40..886eb4b 100644
--- a/libs/binder/ndk/binder_rpc.cpp
+++ b/libs/binder/ndk/binder_rpc.cpp
@@ -255,7 +255,7 @@
                     "new variant was added to the ABinderRpc_ConnectionInfo and this needs to be "
                     "updated.");
         }
-        return OK;
+        return STATUS_OK;
     };
     sp<IBinder> accessorBinder = android::createAccessor(String16(instance), std::move(generate));
     if (accessorBinder == nullptr) {
@@ -321,7 +321,7 @@
     // This AIBinder needs a strong ref to pass ownership to the caller
     binder->incStrong(nullptr);
     *outDelegator = binder.get();
-    return OK;
+    return STATUS_OK;
 }
 
 ABinderRpc_ConnectionInfo* ABinderRpc_ConnectionInfo_new(const sockaddr* addr, socklen_t len) {