cronet import: exclude .gitignore from import am: 2bbe771ceb

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2498881

Change-Id: Id5eaa9997b577b1c7c9d42549faded5b978ac5ae
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>