fix: Kit Initialization & De-Initialization. (#398)

Fix for Kit Initialization & De-Initializationg.
Underlying issues is calling fetchConfig when no kit instance is assigned to KitFrameworkManager, therefore the because the instance is null, we cant pass the kits to to apiClient.
Removing empty validation in ConfigManager since this is a valid case.

Author: markvdouw

android-core/src/main/java/com/mparticle/internal/ConfigManager.java

@@ -319,12 +319,10 @@ void saveConfigJson(JSONObject coreConfig, JSONArray kitConfig, String etag, Str
                     .putString(Constants.PrefKeys.ETAG, etag)
                     .putString(Constants.PrefKeys.IF_MODIFIED, lastModified)
                     .apply();
-            if (kitConfigString == null || (kitConfigString != null && !kitConfigString.isEmpty())) {
-                getKitConfigPreferences()
-                        .edit()
-                        .putString(KIT_CONFIG_KEY, kitConfigString)
-                        .apply();
-            }
+            getKitConfigPreferences()
+                    .edit()
+                    .putString(KIT_CONFIG_KEY, kitConfigString)
+                    .apply();
         } else {
             Logger.debug("clearing current configurations");
             clearConfig();

android-core/src/main/java/com/mparticle/internal/KitFrameworkWrapper.java

@@ -70,6 +70,7 @@ public void loadKitLibrary() {
                 KitManager kitManager = constructor.newInstance(mContext, mReportingManager, mCoreCallbacks, mOptions);
                 JSONArray configuration = mCoreCallbacks.getLatestKitConfiguration();
                 Logger.debug("Kit Framework loaded.");
+                this.mKitManager = kitManager;
                 if (!MPUtility.isEmpty(configuration)) {
                     Logger.debug("Restoring previous Kit configuration.");
                     kitManager
@@ -81,7 +82,6 @@ public void loadKitLibrary() {
                                     }
                             );
                 } else {
-                    mKitManager = kitManager;
                     updateDataplan(mCoreCallbacks.getDataplanOptions());
                 }
             } catch (Exception e) {