Refactored single use of remove to a write

* This lets us clean up a non-optimized code path

Author: jkasten2

OneSignalSDK/onesignal/src/main/java/com/onesignal/OneSignalPrefs.java

@@ -194,7 +194,7 @@ private static Object get(String prefsName, String key, Class type, Object defVa
                 return true;
 
             Object cachedValue = pref.get(key);
-            if (cachedValue != null)
+            if (cachedValue != null || pref.containsKey(key))
                 return cachedValue;
         }
 
@@ -217,22 +217,6 @@ else if (type.equals(Object.class))
         return defValue;
     }
 
-    // TODO: Removes could be optimized as well.
-    //        running applying here for safely for now.
-    static void remove(String prefsName, String key) {
-        HashMap<String, Object> pref = prefsToApply.get(prefsName);
-        synchronized (pref) {
-            pref.remove(key);
-        }
-
-        SharedPreferences prefs = getSharedPrefsByName(prefsName);
-        if (prefs != null) {
-            SharedPreferences.Editor editor = prefs.edit();
-            editor.remove(key);
-            editor.apply();
-        }
-    }
-
     private static synchronized SharedPreferences getSharedPrefsByName(String prefsName) {
         if (OneSignal.appContext == null)
             return null;

OneSignalSDK/onesignal/src/main/java/com/onesignal/TrackGooglePurchase.java

@@ -231,7 +231,8 @@ public void onSuccess(String response) {
 
                      OneSignalPrefs.saveString(OneSignalPrefs.PREFS_PLAYER_PURCHASES,
                              OneSignalPrefs.PREFS_PURCHASE_TOKENS, purchaseTokens.toString());
-                     OneSignalPrefs.remove(OneSignalPrefs.PREFS_PLAYER_PURCHASES, OneSignalPrefs.PREFS_EXISTING_PURCHASES);
+                     OneSignalPrefs.saveBool(OneSignalPrefs.PREFS_PLAYER_PURCHASES,
+                              OneSignalPrefs.PREFS_EXISTING_PURCHASES, true);
 
                      newAsExisting = false;
                      isWaitingForPurchasesRequest = false;