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

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

Change-Id: Iff1c910f97a34f421df95abb2875b813371931ed
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>