Merge "Specify is_fixed_read_only: true for net security mainline trunk stable flag" into main am: f851ae1e82 am: 48d28c81a6

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3234843

Change-Id: If133e1cd92a3a1316d0171435508f2f64efcffd4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>