Address Xcode 14.3 build warnings and a few typos

[paulb777]

Fix #11059

[google-oss-bot]

Coverage Report ¹

Affected Products

• FirebaseDatabase-iOS-FirebaseDatabase.framework

  Overall coverage changed from 57.14% (43cd9c2) to 57.16% (24ec0c7) by +0.02%.

  Filename	Base (43cd9c2)	Merge (24ec0c7)	Diff
  FIRRetryHelper.m	83.33%	88.10%	+4.76%

• FirebaseFirestore-iOS-FirebaseFirestore.framework

  Overall coverage changed from 88.27% (43cd9c2) to 88.23% (24ec0c7) by -0.04%.

  Filename	Base (43cd9c2)	Merge (24ec0c7)	Diff
  exception.cc	84.21%	23.68%	-60.53%
  exception_apple.mm	65.52%	96.55%	+31.03%
  leveldb_key.cc	98.33%	98.82%	+0.49%
  leveldb_remote_document_cache.cc	94.61%	96.41%	+1.80%
  ordered_code.cc	94.39%	93.90%	-0.49%
  task.cc	96.52%	94.78%	-1.74%

• FirebaseMessaging-iOS-FirebaseMessaging.framework

  Overall coverage changed from 59.80% (43cd9c2) to 60.11% (24ec0c7) by +0.30%.

  Filename	Base (43cd9c2)	Merge (24ec0c7)	Diff
  FIRMessagingExtensionHelper.m	69.20%	78.57%	+9.38%
  FIRMessagingPendingTopicsList.m	89.80%	89.02%	-0.78%

Test Logs

• Base (43cd9c2): https://github.com/firebase/firebase-ios-sdk/actions/runs/4580257544
• Merge (24ec0c7): https://github.com/firebase/firebase-ios-sdk/actions/runs/4598612032

1. https://storage.googleapis.com/firebase-sdk-metric-reports/stzmVLu4iF.html