Add base64 externs for ReactNative build

[schmidt-sebastian]

Fixes #2667

[google-oss-bot]

Binary Size Report

Affected SDKs

• @firebase/firestore

  Type	Base (35bc0a2)	Head (4f0ab11)	Diff
  react-native	195 kB	195 kB	+20 B (+0.0%)

• @firebase/firestore/memory

  Type	Base (35bc0a2)	Head (4f0ab11)	Diff
  react-native	149 kB	149 kB	+20 B (+0.0%)

Test Logs

• Base (35bc0a2e): https://github.com/firebase/firebase-js-sdk/actions/runs/140333901
• Head (4f0ab119): https://github.com/firebase/firebase-js-sdk/actions/runs/141013043

[djoiiwalraven]

I just updated firebase-js-sdk, but still getting issue: #2667.

Or will it take sometime before I can update to this version?

Warning I'm getting:
_[Unhandled promise rejection: TypeError: _util.base64.tI is not a function. (In '_util.base64.tI(t, !1)', '_util.base64.tI' is undefined)]

• http://127.0.0.1:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:157852:31 in atob
• http://127.0.0.1:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:140584:29 in fromBase64String

• node_modules/@firebase/firestore/dist/index.rn.esm2017.js:3487:7 in ae#constructor
• node_modules/@firebase/firestore/dist/index.rn.esm2017.js:10097:8 in Zi#xc
• node_modules/@firebase/firestore/dist/index.rn.esm2017.js:9944:13 in Yi#constructor

• http://127.0.0.1:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:150941:41 in
• http://127.0.0.1:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&minify=false&hot=false:148723:37 in

• node_modules/promise/setimmediate/core.js:37:14 in tryCallOne
• node_modules/promise/setimmediate/core.js:123:25 in setImmediate$argument_0
• node_modules/react-native/Libraries/Core/Timers/JSTimers.js:146:14 in _callTimer
• node_modules/react-native/Libraries/Core/Timers/JSTimers.js:194:17 in _callImmediatesPass
• node_modules/react-native/Libraries/Core/Timers/JSTimers.js:458:30 in callImmediates

• [native code]:null in callImmediates

• node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:407:6 in __callImmediates
• node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:143:6 in __guard$argument_0
• node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:384:10 in __guard
• node_modules/react-native/Libraries/BatchedBridge/MessageQueue.js:142:17 in __guard$argument_0

• [native code]:null in flushedQueue
• [native code]:null in callFunctionReturnFlushedQueue_

[schmidt-sebastian]

Sorry - this will be fixed in 7.15.3. We will update you when it has been released.

[schmidt-sebastian]

@Feiyang1 published a new release.