Connectivity OWNERS: let owners modify Android.mk

Since per-file overwrites the directory default, just allowing
build.master@android.com for Android.mk with a per-file rule prevents
the owners of the directory to modify Android.mk files without bypassing
OWNERS check in gerrit.

This patch fixes this issue for Connectivity OWNERS files by explicitly
listing Connectivity members for a few Android.mk files.

Test: build
Change-Id: I9c2a2519c3e7dd27e66334b090e074968b408cbc