[local_mobly_runner] Save a copy of the Mobly config in the logs. am: 10406ca691 am: d8ae937593 am: 6ffe9a4497

Original change: https://android-review.googlesource.com/c/platform/tools/test/mobly_extensions/+/2828890

Change-Id: I270166707d9260c18fa701c0b80d5bba6e674586
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>