samples/assistant/embedded-sdk-python/README: fix code block
samples/assistant/embedded-sdk-python/README: fix code block

Change-Id: I222433a0da0b6698e038d3e3bc371ae6710bc601

GitOrigin-RevId: 4deb1346c10e8e0a8cbd380ba7e6d0f65fbc6fbe

googlesamples/assistant-sdk-python