[mutianf]

gRPC caps inbound messages at 4 MiB by default — a limit sized for a channel that crosses a network. The accelerator's UDS channel doesn't leave the machine: the daemon has already paid the cost of pulling the response off the wire, and all the cap does on this hop is turn an otherwise-fine read into RESOURCE_EXHAUSTED. This sets grpc.max_receive_message_length to 256 MB so the UDS leg is never the narrower of the two.

No test yet. The Go daemon still has its own 4 MiB cap on the sending side, so nothing above 4 MiB actually crosses the socket today and a test would only be asserting on a config value. The test lands once the daemon side is raised.

Only the inbound direction is changed here; grpc.max_send_message_length is untouched.

[gemini-code-assist]

Code Review

This pull request increases the inbound message size limit on the Unix Domain Socket (UDS) channel to 256 MiB for both the asynchronous and synchronous accelerator clients in the Google Cloud Bigtable library. This is achieved by defining _MAX_RECEIVE_MESSAGE_LENGTH and passing it via _CHANNEL_OPTIONS to the insecure_channel constructor, preventing potential RESOURCE_EXHAUSTED errors on local reads. There are no review comments, so I have no feedback to provide.