Fix inconsistent argument names in .h/.cc files

[dconeybe]

These inconsistencies cause warnings when the code is copied into google3 via copybara.

#no-changelog

[google-oss-bot]

Coverage Report ¹

Affected Products

• FirebaseFirestore-iOS-FirebaseFirestore.framework

  Overall coverage changed from 86.64% (6efe4f5) to 86.59% (75a13f1) by -0.05%.

  Filename	Base (6efe4f5)	Merge (75a13f1)	Diff
  exception.cc	73.68%	23.68%	-50.00%
  exception_apple.mm	58.62%	89.66%	+31.03%
  leveldb_key.cc	98.60%	98.81%	+0.22%
  ordered_code.cc	94.15%	93.41%	-0.73%

Test Logs

• Base (6efe4f5): https://github.com/firebase/firebase-ios-sdk/actions/runs/2030612572
• Merge (75a13f1): https://github.com/firebase/firebase-ios-sdk/actions/runs/2035522929

1. https://storage.googleapis.com/firebase-sdk-metric-reports/qModvk4VNO.html