Deprecate mkbootimg_args.json by fully support "--format=mkbootimg" am: 07c6063146 am: de73fd2a36 am: 54e2cc4c57 am: db5515fea9

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/1693414

Change-Id: Ib6e80a642c6b20d889837da50566a151dd6afed5