Sync with libnativehelper refactoring

jniGetFDFromFileDescriptor() is now a legacy method and moved to a
separate header.

Bug: 151443957
Bug: 158749603
Test: m
Change-Id: Ifb5221f3d5a0dee61599ae65800c2cf2218e98ab
Merged-In: Ifb5221f3d5a0dee61599ae65800c2cf2218e98ab
Exempt-From-Owner-Approval: cherry pick
(cherry picked from commit 17706453)