Revert "Revert "Merge branch 'ndk21' into 'master'""

This reverts commit 999b15a9.
10 jobs for master in 37 minutes and 24 seconds
Status Job ID Name Coverage
  Test
passed #404707642
debian_testing

00:12:41

passed #407429415
fedora_latest

00:12:14

passed #404707648
gradle

00:00:35

passed #404707646
lint_format_safety_bandit_checks

00:02:45

passed #404707641
metadata_v0

00:04:59

passed #404707645
pip_install

00:01:42

passed #404707640
test

00:25:09

passed #404707643
ubuntu_lts_ppa

00:16:55

passed #404707644
ubuntu_xenial_pip

00:10:31

failed #404707647
fedora_latest

00:00:29