enhance(main/gst-plugins-bad): Add support for h264 codec

[Biswa96]

• Before:

$ gst-discoverer-1.0 Big_Buck_Bunny_360_10s_1MB.mp4
Analyzing file:///sdcard/samples/Big_Buck_Bunny_360_10s_1MB.mp4
Done discovering file:///sdcard/samples/Big_Buck_Bunny_360_10s_1MB.mp4
Missing plugins
 (gstreamer|1.0|gst-discoverer-1.0|H.264 (High Profile) decoder|decoder-video/x-h264, level=(string)3.1, profile=(string)high, coded-picture-structure=(string)frame, chroma-format=(string)4:2:0, bit-depth-luma=(uint)8, bit-depth-chroma=(uint)8)

• After:

$ gst-discoverer-1.0 Big_Buck_Bunny_360_10s_1MB.mp4
Analyzing file:///sdcard/samples/Big_Buck_Bunny_360_10s_1MB.mp4
Done discovering file:///sdcard/samples/Big_Buck_Bunny_360_10s_1MB.mp4

Properties:
  Duration: 0:00:10.000000000
  Seekable: yes
  Live: no
  container #0: Quicktime
    video #1: H.264 (High Profile)
      Stream ID: bba71162bb7c910da6adf04b41a033ff147d4758732a28884a87bb11928d49ad/001
      Width: 640
      Height: 360
      Depth: 24
      Frame rate: 30/1
      Pixel aspect ratio: 1/1
      Interlaced: false
      Bitrate: 789701
      Max bitrate: 0

• This adds /data/data/com.termux/files/usr/lib/gstreamer-1.0/libgstopenh264.so plugin.