WIP fix: add null check for extras

[jinliu9508]

READ AND DELETE THIS SECTION BEFORE SUBMITTING PR

• Fill out each REQUIRED section
• Fill out OPTIONAL sections, remove section if it doesn't apply to your PR
• Read and fill out each of the checklists below
• Remove this section after reading

Description

One Line Summary

REQUIRED - Very short description that summaries the changes in this PR.

Details

Motivation

REQUIRED - Why is this code change being made? Or what is the goal of this PR? Examples: Fixes a specific bug, provides additional logging to debug future issues, feature to allow X.

Scope

RECOMMEND - OPTIONAL - What is intended to be effected. What is known not to change. Example: Notifications are grouped when parameter X is set, not enabled by default.

OPTIONAL - Other

OPTIONAL - Feel free to add any other sections or sub-sections that can explain your PR better.

Testing

Unit testing

OPTIONAL - Explain unit tests added, if not clear in the code.

Manual testing

RECOMMEND - OPTIONAL - Explain what scenarios were tested and the environment.
Example: Tested opening a notification while the app was foregrounded, app build with Android Studio 2020.3 with a fresh install of the OneSignal example app on a Pixel 6 with Android 12.

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
  • If it is hard to explain how any codes changes are related to each other then it most likely needs to be more than one PR
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
  • Simplify with less code, followed by splitting up code into well named functions and variables, followed by adding comments to the code.
• I have reviewed this PR myself, ensuring it meets each checklist item
  • WIP (Work In Progress) is ok, but explain what is still in progress and what you would like feedback on. Start the PR title with "WIP" to indicate this.

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