fix invalid module names

[muncus]

the following packages do not use fully qualified module names, which results in 'ambiguous import' errors.

• [ ] ./compute/quickstart
• [ ] ./internal/gomodversiontest
• [ ] ./appengine_flexible/static_files
• [ ] ./appengine_flexible/helloworld
• [ ] ./appengine_flexible/analytics
• [ ] ./appengine_flexible/redis
• [ ] ./appengine_flexible/datastore
• [ ] ./appengine_flexible/pubsub
• [ ] ./appengine_flexible/storage

[muncus]

fixed by #3743