Allow ssr_detector_app writes to system_app_data_file. am: 8723e1ed66

Original change: https://android-review.googlesource.com/c/device/google/sunfish-sepolicy/+/2320200

Change-Id: I00aad6206065d4d4d92c54269a397daf1ae0f157
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>