chore(functions/firebase): split samples into dirs

[ace-n]

[snippet-bot[bot]]

Here is the summary of changes.

You are about to add 6 region tags.

• functions/firebase/helloAnalytics/index.js:17, tag functions_firebase_analytics
• functions/firebase/helloAuth/index.js:15, tag functions_firebase_auth
• functions/firebase/helloFirestore/index.js:15, tag functions_firebase_firestore
• functions/firebase/helloRTDB/index.js:15, tag functions_firebase_rtdb
• functions/firebase/helloRemoteConfig/index.js:15, tag functions_firebase_remote_config
• functions/firebase/makeUpperCase/index.js:15, tag functions_firebase_reactive

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