Change softvpx buffer count to 10

Some cts tests made implicity assumption that the number of buffers
is less than 16. When the decoder has 16 or more input buffers, it
could queue more input buffers without blocking before the first
output comes out, tests waiting for the output might fail.

Changing buffer count to 10, as it still allows 60fps content to
buffer >150ms.

Also added a few missing OMX param check.

Test: Youtube/Exoplayer HDR 1080p60 playback (with media service
cpu set to top-app) and observe no framedrops;
Failing CTS test in bug.

bug: 75976396
bug: 76145803
Change-Id: Ie27583e6519a3dbadc7c993022a5af830fb250a9