Getter for WorkManager considers the app context

* We were getting the WorkManager instance via `WorkManagerImpl.getInstance()` and initializing it with a blank Configuration when the getter returned null.
* However, we should use `WorkManagerImpl.getInstance(Context)` instead as this getter will allow for on-demand initialization with the app's custom WorkManager.

Author: nan-li

OneSignalSDK/onesignal/src/main/java/com/onesignal/OSWorkManagerHelper.kt

@@ -27,40 +27,58 @@
 
 package com.onesignal
 
-import android.annotation.SuppressLint
 import android.content.Context
 import androidx.work.Configuration
 import androidx.work.WorkManager
-import androidx.work.impl.WorkManagerImpl
 
 object OSWorkManagerHelper {
-    /**
-     * Helper method to provide a way to check if WorkManager is initialized in this process.
-     *
-     * This is effectively the `WorkManager.isInitialized()` public method introduced in androidx.work:work-*:2.8.0-alpha02.
-     * Please see https://android-review.googlesource.com/c/platform/frameworks/support/+/1941186.
-     *
-     * @return `true` if WorkManager has been initialized in this process.
-     */
-    @SuppressWarnings("deprecation")
-    @SuppressLint("RestrictedApi")
-    private fun isInitialized(): Boolean {
-        return WorkManagerImpl.getInstance() != null
-    }
-
     /**
      * If there is an instance of WorkManager available, use it. Else, in rare cases, initialize it ourselves.
      *
      * Calling `WorkManager.getInstance(context)` directly can cause an exception if it is null.
+     * However, this is the appropriate way to check as the non-throwing `WorkManager.getInstance()`
+     * method does not allow the opportunity for on-demand initialization with custom WorkManager.
+     *
+     * The purpose of this helper is to work around this bug - https://issuetracker.google.com/issues/258176803
      *
      * @return an instance of WorkManager
      */
     @JvmStatic
     @Synchronized
     fun getInstance(context: Context): WorkManager {
-        if (!isInitialized()) {
-            WorkManager.initialize(context, Configuration.Builder().build())
+        return try {
+            WorkManager.getInstance(context)
+        } catch (e: IllegalStateException) {
+            /*
+            This aims to catch the IllegalStateException "WorkManager is not initialized properly..." -
+            https://androidx.tech/artifacts/work/work-runtime/2.8.1-source/androidx/work/impl/WorkManagerImpl.java.html
+             */
+            OneSignal.Log(OneSignal.LOG_LEVEL.ERROR, "OSWorkManagerHelper.getInstance failed, attempting to initialize: ", e)
+            initializeWorkManager(context)
+            WorkManager.getInstance(context)
+        }
+    }
+
+    /**
+     * This method is called in rare cases to initialize WorkManager ourselves.
+     */
+    private fun initializeWorkManager(context: Context) {
+        try {
+            /*
+            Note: `WorkManager.getInstance(context)` should already initialize WorkManager when the
+            application implements Configuration.Provider. However, as a further safeguard, let's detect
+            for this when we attempt to initialize WorkManager.
+             */
+            val configuration = (context.applicationContext as? Configuration.Provider)?.workManagerConfiguration ?: Configuration.Builder().build()
+            WorkManager.initialize(context, configuration)
+        } catch (e: IllegalStateException) {
+            /*
+            This catch is meant for the exception -
+            https://android.googlesource.com/platform/frameworks/support/+/60ae0eec2a32396c22ad92502cde952c80d514a0/work/workmanager/src/main/java/androidx/work/impl/WorkManagerImpl.java#177
+            1. We lost the race with another call to  WorkManager.initialize outside of OneSignal.
+            2. It is possible for some other unexpected error is thrown from WorkManager.
+             */
+            OneSignal.Log(OneSignal.LOG_LEVEL.ERROR, "OSWorkManagerHelper initializing WorkManager failed: ", e)
         }
-        return WorkManager.getInstance(context)
     }
 }