Add package/modules/Connectivity bpf_headers path

Following CLs will move frameworks/libs/net to packages/modules/Connectivity.
This CL is a preparation for that.

Bug: 296014682
Test: m
(cherry picked from https://android-review.googlesource.com/q/commit:44591557f4bf64c36b831152cb75fc68b8cdad59)
Merged-In: Ie6483d1e5dfbf6c4745c10d3bb031344368c8c8f

Change-Id: Ie6483d1e5dfbf6c4745c10d3bb031344368c8c8f