fix(firebase_analytics): allow null values for setDefaultEventParameters() which removes defaults. Permissible on android and iOS.

[ueman]

Description

As described in the linked issue, setDefaultEventParameters should accept Map<String, Object?>?.

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In order to reset default event parameters, you should set the corresponding key to null. In order to reset all parameters, you should pass null.
That's what the documentation for Android and iOS says.

Android:
Parameters to be added to the map of parameters added to every event. They will be added to the map of default event parameters, replacing any existing parameter with the same name. Valid parameter values are String, long, and double. Setting a key's value to null will clear that parameter. Passing in a null bundle will clear all parameters.

iOS:
Parameters to be added to the dictionary of parameters added to every event. They will be added to the dictionary of default event parameters, replacing any existing parameter with the same name. Valid parameters are String, Int, and Double. Setting a key’s value to NSNull() will clear that parameter. Passing in a nil dictionary will clear all parameters.

However, the Dart code only accepts Map<String, Object> according to the docs.

Since this fixes a bug, this is not a breaking change.

Related Issues

Fixes #9005.

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Breaking Change

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[Lyokone]

Hello @ueman, thanks for your contribution :)
LGTM, just need to rebase from master for CI to go green :)

[russellwheatley]

Do you mind adding an e2e test here which also tests setDefaultEventParameters() passing a null value? Thanks 🙏

[ueman]

Do you mind adding an e2e test here which also tests setDefaultEventParameters() passing a null value? Thanks 🙏

Yes, will do

[ueman]

@russellwheatley Done ✅