Due to the restriction of Treble, update_engine cannot access to OTA
packages located on non-core domain area.
(e.g. /data/vendor/upgrade/xxx.zip)
To solve such problem, update_engine needs to accept a file descriptor
(FD) of OTA package file instead of its URI. Accordingly, UpdateEngine
also needs to add a new interface of applyPayload which accepts FD.
Test: Manual update
Bug: 130209137
Change-Id: Ic924445c4abf27fd7dc111c74b972ac7ff9ffa6b
bcc56339bb