Google starts rolling out Android 7.1.1 DP2 to supported devices, such as Nexus 5X, Nexus 6P, Pixel C and Nexus 9. This is the last developer preview of Android 7.1.1 before the final release and includes various new features, optimization and bug fixes. People who have already signed up for Android Beta program will receive the Android 7.1.1 Nougat Developer Preview 2 (NPF26F) OTA update in the coming days.
With Developer Preview 2, Google has also updating the SDK build and platform tools in Android Studio. The latest version of the support library (25.0.1) has also available for developers to add image keyboard support, bottom navigation, and other features to apps for devices running API Level 25 or earlier.
Android 7.1.1 Nougat is the next major Android OS update, as it includes various new features, performance tweaks as well as API changes (API level 25) for developers. Android 7.1.1 Developer Preview 2 (NPF26F) is the near-final system images for final testing and the final stable build will be released in December, next month.
According to developer preview timeline, the final build of Android 7.1.1 will be rolled out next month (December) to the Nexus 6, Nexus 5X, Nexus 6P, Nexus Player, Nexus 9, and Pixel C, General Mobile 4G (Android One), Pixel and, Pixel XL.
To get Android 7.1.1 DP2 right now, enroll your supported device in the Android beta program [HERE]. You will get the OTA update on the developer preview or you can download the factory images and flash them manually.
If you have difficulty in downloading the OTA update on your device, follow the manual installation method. This method will ERASE your device, so make sure you have backed everything up first. It is recommended for tech-savvy users only.
1. First, download the Android factory image (DP2) for your device from here
2. Setup ADB and fastboot drives on your PC and follow the flashing instruction as described here
Note that, this is a developer preview, so it can contain bugs that can affect normal functioning of the device. (Source)