android crash vp9 fake alpha

Given the following video https://www.dropbox.com/scl/fi/i1yru4g9zjilx0dp63e8u/Chat-Frame_VP9.zip?rlkey=fziv054piyft4r49q10unky0v&dl=1 with properties:

"codec_name": "vp9", …
"pix_fmt": "yuv420p",
…
"tags": {…
                "alpha_mode": "1",
                …
}

But no actual alpha data. This assert is hit:

11-03 13:04:12.267 17932 17932 F DEBUG   : Abort message: '../../modules/video_output/opengl/interop_android.c:101: int tc_anop_update(const struct vlc_gl_interop *, uint32_t *, const int32_t *, const int32_t *, picture_t *, const size_t *): assertion "pic->context" failed'

On latest master. Full logs https://code.videolan.org/-/snippets/1825