Sync with libnativehelper refactoring

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

Bug: 151443957
Bug: 158749603
Test: m
Change-Id: Icd06e9a315680c2251dbb9032a904dd6d66aa359
Merged-In: Icd06e9a315680c2251dbb9032a904dd6d66aa359
Exempt-From-Owner-Approval: cherry pick
(cherry picked from commit 3ada1136)