[VCN07.3] Add NOT_VCN_MANAGED for NetworkAgent implementations am: 336013c3dc

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Wifi/+/1563135

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I5b148e6c855c1b8c0367e345beb9f1a1be438728