Recently a tag named master-p has appeared on ASOP repository which reveals that Google has already started testing the next iteration called Android P or Android 9.0 on devices like Google Pixel and Pixel XL which codenamed has been spotted as Sailfish and Marlin.The new PPR1 is the name where Google Engineer is referencing the repository corresponds to new three part Android Build name which was earlier introduced on Android Oreo and is expected to use in a future iteration of Android OS.
Apart from that some of the next iteration of Android will be named as Android P as of now there is no info what will be the letter P stands for. The two Googler discuss a CTS testing change, with one of them telling they are not sure if OMR1 code is needed which they had copied from Google internal repository to Android P branch of ASOP, which suggests that Google will never release the maintenance update for Android Oreo which they did with Android N which means that Android 8.1 will never arrive.Google also skipped the Android 6.1 update with Android M earlier.
Google launched the Android O last week with recently some Google Pixel device received the official final update.The new Android O comes with faster app opening, improved notifications, improved performance, and stability enhancements.