Motorola has started to roll out 2nd Generation Moto E XT1521 (4G model) Android 5.1.1 Lollipop OTA update along with Stagefright patch in India. Moto E users in India will receive the OTA update notification on their device in the coming days, if you are on the stock Android 5.0.2 Lollipop firmware.
Besides the Stagefright patch, the new Android 5.1.1 Lollipop update will improve battery life and performance of the Moto E XT1521. The best part of this update is that it fixes the memory leak and other bugs found in the previous update. Overall, you will definitely notice a performance boost while using the phone.
Note that the size of the OTA update is about 402.2 MB and the system version is 23.51.65.en.03. In addition, this may be the last official update, as Motorola has no plan for Android 6.0 Marshmallow update for Moto E 2015.
How to Install OTA Update in Moto E XT1521 (4G)
1. Go to settings -> About ->Check for Update.
2. If system update is available, tap on Yes, I’m In and select Wi-Fi/Mobile data and tap on done.
Note: If you have not received the notification, instead received ‘Your software is up to date’ message, then switch off your phone and boot into stock recovery mode. From recovery, wipe cache partition. Reboot your phone. Then check for updates again and install the system update.
3. Once the process is completed, your Moto E 2015 will reboot to Android 5.1
Note: Once the installation process finished, switch off your phone, boot into recovery mode, and then clear Cache Partition. It will remove glitches and temporary bugs. (Source)