fix: clean up all javadoc warnings (#365)

Author: jaeopt

android-sdk/src/main/java/com/optimizely/ab/android/sdk/OptimizelyClient.java

@@ -810,6 +810,7 @@ public OptimizelyUserContext createUserContext(@NonNull String userId) {
 
     /**
      * Convenience method for adding DecisionNotification Handlers
+     * @param handler a NotificationHandler to be added
      * @return notificationId or -1 if notification is not added
      */
     @Nullable
@@ -824,6 +825,7 @@ public int addDecisionNotificationHandler(NotificationHandler<DecisionNotificati
 
     /**
      * Convenience method for adding TrackNotification Handlers
+     * @param handler a NotificationHandler to be added
      * @return notificationId or -1 if notification is not added
      */
     public int addTrackNotificationHandler(NotificationHandler<TrackNotification> handler) {
@@ -838,6 +840,7 @@ public int addTrackNotificationHandler(NotificationHandler<TrackNotification> ha
 
     /**
      * Convenience method for adding UpdateConfigNotification Handlers
+     * @param handler a NotificationHandler to be added
      * @return notificationId or -1 if notification is not added
      */
     public int addUpdateConfigNotificationHandler(NotificationHandler<UpdateConfigNotification> handler) {
@@ -852,6 +855,7 @@ public int addUpdateConfigNotificationHandler(NotificationHandler<UpdateConfigNo
 
     /**
      * Convenience method for adding LogEvent Notification Handlers
+     * @param handler a NotificationHandler to be added
      * @return notificationId or -1 if notification is not added
      */
     public int addLogEventNotificationHandler(NotificationHandler<LogEvent> handler) {

android-sdk/src/main/java/com/optimizely/ab/android/sdk/OptimizelyManager.java

@@ -325,8 +325,8 @@ public void run() {
 
     /** This function will first try to get datafile from Cache, if file is not cached yet
      * than it will read from Raw file
-     * @param context
-     * @param datafileRes
+     * @param context     any {@link Context} instance
+     * @param datafileRes the R id that the data file is located under.
      * @return datafile
      */
     public String getDatafile(Context context,@RawRes Integer datafileRes){

shared/src/main/java/com/optimizely/ab/android/shared/DatafileConfig.java

@@ -1,5 +1,5 @@
 /****************************************************************************
- * Copyright 2018, Optimizely, Inc. and contributors                        *
+ * Copyright 2018,2021, Optimizely, Inc. and contributors                   *
  *                                                                          *
  * Licensed under the Apache License, Version 2.0 (the "License");          *
  * you may not use this file except in compliance with the License.         *
@@ -120,7 +120,7 @@ public static DatafileConfig fromJSONString(String jsonString) {
     /**
      * To string either returns the proejct id as string or a concatenated string of project id
      * delimiter and environment key.
-     * @return
+     * @return the string identification for the DatafileConfig
      */
     @Override
     public String toString() {

shared/src/main/java/com/optimizely/ab/android/shared/WorkerScheduler.java

@@ -49,7 +49,7 @@ public static void unscheduleService(Context context, String workerId) {
      * @param workerId worker id
      * @param clazz class based on ListenableWorker
      * @param data androidx.work.Data
-     * @param interval
+     * @param interval the interval for the repeated service
      */
     public static void scheduleService(Context context, String workerId, Class clazz, Data data, long interval) {
         WorkManager.getInstance(context).cancelAllWorkByTag(workerId);