logd: inherit android_get_control_file()

Setup and then collect from the environment /proc/kmsg and /dev/kmsg
file descriptors. Do not do so for logcat --reinit.

Test: gTest logd-unit-tests, liblog-unit-tests and logcat-unit-tests
Bug: 32450474
Change-Id: Ied537ca561fcd4e71a9ad9c57398a23ba23f6ced