In addition to the other properties, try to obtain the right
CGColorSpace and set it as well, else it could lead to a CVBuffer
tagged as BT.2020 but with a CGColorSpace indicating BT.709.
Therefore it is essential for consistency to set a colorspace
according to the other values, or if none can be obtained (for example
because the other values are all unspecified) unset it as well.
Fix#10884
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>