libbinder: update 'TODO' comments for RPC

Some stale/duplicated removed. Some bug numbers updated. Some added
based on what I've been thinking about.

Bug: N/A
Test: N/A
Change-Id: I963bec5085b4d6868126d90c12c62cd64f31ddc0
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 232a70c..ebba375 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -206,6 +206,7 @@
             status_t status = writeInt32(1); // non-null
             if (status != OK) return status;
             RpcAddress address = RpcAddress::zero();
+            // TODO(b/167966510): need to undo this if the Parcel is not sent
             status = mSession->state()->onBinderLeaving(mSession, binder, &address);
             if (status != OK) return status;
             status = address.writeToParcel(this);