[FR] Improvement: Change updateChildren parameter to Map<String, ?>

[chrylis]

Is your feature request related to a problem? Please describe.
Various builders (e.g., Map.of) and language features (e.g., Groovy and Kotlin inline maps) create Map instances whose V bound is more strict than Object. Currently, the DatabaseRef#updateChildren[Async] interface won't accept these instances because it is defined as accepting Map<String, Object>.

Describe the solution you'd like
Since these method consume the map and do not modify it, they could be defined as Map<String, ?> to accept a map with any generic value type with no backwards incompatibility or other code changes.

Describe alternatives you've considered
Otherwise, passing in maps usually requires an explicit type declaration instead of var or an inline builder.

[google-oss-bot]

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