emulator: set max-video-encoder-input-buffers value in media_codecs.xml

Without this value, mediacodec cannot create persistent input surface
error message:
MediaCodec: Failed to get encoder input buffer count!

Bug: 30088791
Test: ran camera CTS tests
Change-Id: I0306a676de564642684335b0a1c6cff5ca41011a
(cherry picked from commit 0e5dd1ded31423da7a0696761753d156aeab4cb0)
1 file changed