drm_hwcomposer: OWNERS: Update John Stultz' email adddress am: 47875fade6 am: 080c9b2aab

Original change: https://android-review.googlesource.com/c/platform/external/drm_hwcomposer/+/2143434

Change-Id: I2d2cbb8fcf9149ebae4528ff9595c4fbceaba9bf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>