drm_hwcomposer: OWNERS: Update John Stultz' email adddress am: 47875fade6 am: 080c9b2aab am: 6ac06cd307 am: 4b2e3cfc85

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

Change-Id: I8370ffd7ea26ddb8e52ffe806f9d224bfaa3744d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>