libbinder: Print the iov number in RPC log messages

Bug: 224644083
Test: m
Change-Id: Id6f981911491d543561b0306b25dd4ef44fa8e5e
diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 173e30a..6d89064 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -313,7 +313,8 @@
                            const sp<RpcSession>& session, const char* what, iovec* iovs, int niovs,
                            const std::function<status_t()>& altPoll) {
     for (int i = 0; i < niovs; i++) {
-        LOG_RPC_DETAIL("Sending %s on RpcTransport %p: %s", what, connection->rpcTransport.get(),
+        LOG_RPC_DETAIL("Sending %s (part %d of %d) on RpcTransport %p: %s",
+                       what, i + 1, niovs, connection->rpcTransport.get(),
                        android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str());
     }
 
@@ -343,7 +344,8 @@
     }
 
     for (int i = 0; i < niovs; i++) {
-        LOG_RPC_DETAIL("Received %s on RpcTransport %p: %s", what, connection->rpcTransport.get(),
+        LOG_RPC_DETAIL("Received %s (part %d of %d) on RpcTransport %p: %s",
+                       what, i + 1, niovs, connection->rpcTransport.get(),
                        android::base::HexString(iovs[i].iov_base, iovs[i].iov_len).c_str());
     }
     return OK;