adding get and save LastTimeInAppDismissed to OneSignalPrefs

This is taking a Date and transforming it into a string before saving it in OneSignalPrefs. The format is using the format from the Date class's toString() method

Author: emawby

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

@@ -10,8 +10,12 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Date;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 
 class OSInAppMessageRepository {
@@ -447,6 +451,33 @@ void saveIAMs(final String inAppMessages) {
                 inAppMessages);
     }
 
+    void saveLastTimeInAppDismissed(Date lastTimeInAppDismissed) {
+        String lastTimeDismissedString = lastTimeInAppDismissed != null ?
+                lastTimeInAppDismissed.toString() : null;
+        sharedPreferences.saveString(
+                OneSignalPrefs.PREFS_ONESIGNAL,
+                OneSignalPrefs.PREFS_OS_LAST_TIME_IAM_DISMISSED,
+                lastTimeDismissedString);
+    }
+
+    @Nullable
+    Date getLastTimeInAppDismissed() {
+        String lastTimeDismissedString = sharedPreferences.getString(
+                OneSignalPrefs.PREFS_ONESIGNAL,
+                OneSignalPrefs.PREFS_OS_LAST_TIME_IAM_DISMISSED, null);
+        if (lastTimeDismissedString == null) {
+            return null;
+        }
+        // This pattern matches the pattern used by the Date class's toString() method
+        SimpleDateFormat format = new SimpleDateFormat("EEE MMM dd HH:mm:ss zzz yyyy", Locale.ENGLISH);
+        try {
+            return format.parse(lastTimeDismissedString);
+        } catch (ParseException exception) {
+            OneSignal.onesignalLog(OneSignal.LOG_LEVEL.ERROR, exception.getLocalizedMessage());
+            return null;
+        }
+    }
+
     private void printHttpSuccessForInAppMessageRequest(String requestType, String response) {
         logger.debug("Successful post for in-app message " + requestType + " request: " + response);
     }

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

@@ -113,6 +113,7 @@ class OneSignalPrefs {
     public static final String PREFS_OS_IMPRESSIONED_IAMS = "PREFS_OS_IMPRESSIONED_IAMS";
     public static final String PREFS_OS_CLICKED_CLICK_IDS_IAMS = "PREFS_OS_CLICKED_CLICK_IDS_IAMS";
     public static final String PREFS_OS_PAGE_IMPRESSIONED_IAMS = "PREFS_OS_PAGE_IMPRESSIONED_IAMS";
+    public static final String PREFS_OS_LAST_TIME_IAM_DISMISSED = "PREFS_OS_LAST_TIME_IAM_DISMISSED";
 
     // Player Purchase Keys
     static final String PREFS_PURCHASE_TOKENS = "purchaseTokens";