Fix Firebase Mac builds from swift build command
Fix Firebase Mac builds from swift build command

Pulling this library in using a macOS target results in a package resolution error. This ensures the macOS version is specified in the package manifest
```
error: the library 'GoogleAppMeasurementWithoutAdIdSupportTarget' requires macos 10.10, but depends on the product 'GULAppDelegateSwizzler' which requires macos 10.12; consider changing the library 'GoogleAppMeasurementWithoutAdIdSupportTarget' to require macos 10.12 or later, or the product 'GULAppDelegateSwizzler' to require macos 10.10 or earlier.
```
google/GoogleAppMeasurement,google/GoogleAppMeasurement