Do not write into EglSurfaceTexture after creation

... beacuse it prevents other clients from connecting.
Instead, render/compress black image into output buffers
directly if the input surface texture doesn't have any
buffer yet.

Bug: 301023410
Test: OpenCamera
Test: atest virtual_camera_tests
Change-Id: I289ff00b590c9bc18052ae0cc15a9d7320b8f033