[Feat] Bump native OneSignal SDKs versions

[shepherd-l]

Description

One Line Summary

Updates included OneSignal Android SDK from 5.1.7 to 5.1.8 and OneSignal iOS SDK from 5.1.4 to 5.1.5

Details

Motivation

Apply fixes made in the native SDKs to the Unity wrapper SDK.

Scope

Updated included Android SDK from 5.1.8 to 5.1.9

• Added AndroidManifest option to override In-App Messages gray overlay and dropshadow
  • <meta-data android:name="com.onesignal.inAppMessageHideGrayOverlay" android:value="true"/>
  • <meta-data android:name="com.onesignal.inAppMessageHideDropShadow" android:value="true"/>
• Fixed WorkManager not initialized crash
• Fixed don't re-create user on failed remove alias
• Added network call optimizations
• For full changes, see the native release notes

Updated included iOS SDK from 5.1.4 to 5.1.5

• Added plist option to hide gray overlay and disable dropshadow for In-App Messages
  • OneSignal_in_app_message_hide_gray_overlay
  • OneSignal_in_app_message_hide_drop_shadow
• For full changes, see the native release notes

Testing

Manual testing

Tested OneSignal initialization, app build with Unity 2021.3.10f1 of the OneSignal example App on an iPhone 12 with iOS 15.5.
Added OneSignal_in_app_message_hide_drop_shadow to the plist and set Type Boolean to YES and In-App Message did not display drop shadow.

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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