`kFirebaseInstallationsErrorDomain` missing `NS_SWIFT_NAME`

[ryanwilson]

firebase-ios-sdk/FirebaseInstallations/Source/Library/Public/FirebaseInstallations/FIRInstallationsErrors.h

Line 19 in bdac2b8

extern NSString *const kFirebaseInstallationsErrorDomain;

This is missing the NS_SWIFT_NAME, unfortunately fixing it is a breaking change. It should be named InstallationsErrorDomain.

[paulb777]

Merged #9395 into v9