initialProperties are missing in Android implementation

[sneerin]

Is this a bug report?

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yes

Have you read the Contributing Guidelines?

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Environment

android doesn't have any matching functionality comparing with ios
https://facebook.github.io/react-native/docs/communication-ios.html
there is no initialproperties there.

1. react-native -v:
2. node -v:
3. npm -v:
4. yarn --version:

Then, specify:

• Target Platform:

• Development Operating System:

• Build tools:

Steps to Reproduce

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Expected Behavior

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Actual Behavior

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Reproducible Demo

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[sneerin]

There were no documentation, but I found it in https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/react/ReactRootView.java