Merge tag 'v1.2.2'

libwebp-1.2.2

- 1/11/2022: version 1.2.2
  This is a binary compatible release.
  * webpmux: add "-set bgcolor A,R,G,B"
  * add ARM64 NEON support for MSVC builds (#539)
  * fix duplicate include error in Xcode when using multiple XCFrameworks in a
    project (#542)
  * doc updates and bug fixes (#538, #544, #548, #550)

* tag 'v1.2.2':
  update ChangeLog
  libwebp: Fix VP8EncTokenLoop() progress
  BMP enc: fix the transparency case
  libwebp: do not destroy jpeg codec twice on error
  update ChangeLog
  update NEWS
  man/img2webp.1: update date
  Reword img2webp synopsis command line
  anim_decode: fix alpha blending with big-endian
  webpinfo: fix fourcc comparison w/big-endian
  update ChangeLog
  update NEWS
  bump version to 1.2.2
  update AUTHORS

Bug: webp:541, b/202302177
Change-Id: Iae875b6ec3084157837cc774c94088ca72e8dd91