codecs: h264picture: use g_array_remove_index_fast()

This algorithm is faster than the normal one. The problem is it
disorders the elements in the dpb, but it does not seem to mess
decoders.

Part-of: <gstreamer/gst-plugins-bad!1378>
29 jobs for !1378 with remove_index_fast in 25 minutes and 49 seconds (queued for 1 minute and 32 seconds)
detached
Status Job ID Name Coverage
  Build Docker
passed #3338985
gstreamer
alpine amd64 manifest builder docker

00:01:23

passed #3338983
gstreamer
android docker

00:01:50

passed #3338981
gstreamer
cerbero fedora amd64 docker

00:04:30

passed #3338979
gstreamer
fedora amd64 docker

00:04:25

passed #3338987
gstreamer
gst-indent amd64 docker

00:01:06

 
  Preparation
passed #3338990
gst indent

00:00:21

passed #3338989
manifest

00:00:30

 
  Build
passed #3339006
gstreamer
build cerbero cross-android universal

00:05:41

passed #3339010
gst-ios-13.2
build cerbero cross-ios universal

00:19:13

passed #3339007
gstreamer
build cerbero cross win32

00:03:59

passed #3339008
gstreamer
build cerbero cross win64

00:03:59

passed #3339005
gstreamer
build cerbero fedora x86_64

00:03:31

passed #3339009
gst-macos-10.15
build cerbero macos x86_64

00:09:28

passed #3338997
build clang fedora x86_64

00:07:08

manual #3339004
1809 windows docker allowed to fail manual
build msys2
passed #3338992
build nodebug fedora x86_64

00:05:26

passed #3338994
build static fedora x86_64

00:05:47

passed #3338995
build static nodebug fedora x86_64

00:05:46

passed #3338999
1809 windows docker
build vs2017 amd64

00:13:35

passed #3339001
1809 windows docker
build vs2017 x86

00:13:43

 
  Test
passed #3339011
gstreamer
check fedora

00:07:11

passed #3339012
gstreamer
integration testsuites fedora 1/4

00:14:37

passed #3339013
gstreamer
integration testsuites fedora 2/4

00:12:24

passed #3339014
gstreamer
integration testsuites fedora 3/4

00:14:07

passed #3339015
gstreamer
integration testsuites fedora 4/4

00:13:47

passed #3339016
gstreamer
valgrind bad

00:06:38

 
  Integrate
passed #3339017
cross-android universal examples

00:06:54

passed #3339019
gst-ios-13.2
cross-ios universal examples

00:01:21

passed #3339018
documentation

00:09:39