Fix Pinpoint NullPointerException (#3007)

Co-authored-by: Thomas Leing <[email protected]>

Author: tjleing

aws-android-sdk-pinpoint/src/main/java/com/amazonaws/mobileconnectors/pinpoint/targeting/notification/NotificationClientBase.java

@@ -306,12 +306,16 @@ private boolean initClassesAndMethodsByReflection() {
                 notificationChannelClass = Class.forName("android.app.NotificationChannel"); //API Level 26
             }
             if (!buildMethodsByReflection()) {
+                // make sure that we don't try to use the notificationBuilderClass
+                notificationBuilderClass = null;
                 // fall back to creating the legacy notification.
                 return false;
             }
             return true;
         } catch (final ClassNotFoundException ex) {
             log.debug("Failed to get notification builder classes by reflection : " + ex.getMessage(), ex);
+            // make sure that we don't try to use the notificationBuilderClass
+            notificationBuilderClass = null;
             return false;
         }
     }
@@ -399,6 +403,9 @@ private boolean registerDefaultNotificationChannel() {
         } catch (final NoSuchMethodException ex) {
             log.debug("Failed to get notification channel method getId by reflection. : " + ex.getMessage(), ex);
             return false;
+        } catch (final NullPointerException ex) {
+            log.debug("Reflected methods not successfully created. :" + ex.getMessage(), ex);
+            return false;
         }
     }
 
@@ -589,6 +596,10 @@ private Notification createNotification(final int iconResId, final String title,
             log.debug("Exception while instantiating notification builder or bigTextStyle or bigPictureStyle classes. : " + ex.getMessage(),
                       ex);
             return createLegacyNotification(iconResId, title, contentText, contentIntent);
+        } catch (final NullPointerException ex) {
+            log.debug("Reflected methods not successfully created. : " + ex.getMessage(),
+                    ex);
+            return createLegacyNotification(iconResId, title, contentText, contentIntent);
         }
 
         try {