tflite: Add team email in DIR_METADATA

BUG=b:314854484
TEST=Run `dirmd validate`

Change-Id: I06333234a7fc9cc4ce5e5d00848a0679cf9604a9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tflite/+/5401496
Tested-by: Shik Chen <shik@chromium.org>
Reviewed-by: Tommy Chiang <ototot@google.com>
Auto-Submit: Shik Chen <shik@chromium.org>
Commit-Queue: Tommy Chiang <ototot@google.com>