surfaceflinger: support BT2020_ITU_PQ

Games use BT2020_PQ while videos use BT2020_ITU_PQ usually.  We can
support both and treat them as the same, since the YUV->RGB
conversion happens before the pixel data are uploaded to texture, or
happens inside the GLES driver.

The only caveat is that we treat RGBA1010102/BT2020_ITU_PQ from
media specially.  The hack is also updated in this change.

Test: manual
Change-Id: I1e4b8e0d907af5e5a95cf7fde1a7ea67a4e7da0b