Add support for nv21 video format as found on android

Note that the same code could be used for nv12
Status Job ID Name Coverage
  Test
passed #16641
clazy

00:01:25

passed #16642
qmllint

00:01:24

 
  Build
passed #16646
archlinux

00:01:51

passed #16645
debian-sid

00:01:41

passed #16644
neon-bionic

00:01:27

passed #16643
ubuntu-trusty

00:01:27

 
  Deploy
failed #16649
allowed to fail
android

00:00:01

failed #16647
allowed to fail
linux-appimage

00:00:54

passed #16650
allowed to fail
mac-osxcross

00:05:25

passed #16648
allowed to fail
windows-mxe

00:05:09

 
Name Stage Failure
failed
linux-appimage Deploy
 * KF5Notifications
* Qt5Widgets, Integration with QWidget based desktop styles
* Qt5Qml
* Qt5Core
* Qt5

-- Configuring incomplete, errors occurred!
See also "/builds/kde/kaidan/build/CMakeFiles/CMakeOutput.log".
ERROR: Job failed: exit code 1
failed
android Deploy
Running with gitlab-runner 11.11.2 (ac2a293c)
on fiesta umZyLAru
Using Docker executor with image kdeorg/android-sdk ...
Pulling docker image kdeorg/android-sdk ...
ERROR: Job failed: Error response from daemon: pull access denied for kdeorg/android-sdk, repository does not exist or may require 'docker login' (executor_docker.go:175:1s)