Bug Fixes

• api: When forwarding from Listener onAddresses to Listener2 continue to use onResult (#11688). This fixes a 1.68.1 "IllegalStateException: Not called from the SynchronizationContext" regression (#11662) that could be seen in certain custom NameResolvers
• okhttp: If the frame handler thread is null do not schedule it on the executor (#11716). This fixes a 1.68.1 NullPointerException regression when a custom transportExecutor was provided to the channel and it did not have enough threads to run new tasks

Improvements

• examples: Use xds-enabled server and xds credentials in example-gcp-csm-observability (#11707)