Regen / release vision, texttospeech, iot

[tseaver]

Now that the gapic-generator fix for shared modules is merged. The recent releases of those API libraries all contain the re-introduced module overwrites for shared modules (#5473).

[tseaver]

As of right now:

• vision-0.33.0 has the fix in place. (Re-generate library using vision/synth.py #5530)
• texttospeech-0.2.0does not have the fix in place. (Generate text-to-speech v1 and v1beta1 #5468 actually undid the manual fix from Avoid overwriting '__module__' of messages from shared modules. #5364)
• iot does not have the fix in place.

[busunkim96]

I assume this is now out of date, closing.