It is necessary in order to distinguish 2 different reasons for referencing the compiled-in locale.
1. Some code just needs to pass the locale value on to logic that actually uses it.
2. Other code uses the locale value to select locale-specific user-visible data and behavior.
Code modified by this change is of the first kind and should use `goog.getLocale()` in the future.
Note: there are still references to the `goog.LOCALE` in Angular codebase, but they are of second type.
PR Close#43089