DO NOT MERGE: Build a static bspatch for recovery.

The recovery image must include only static binary. This patch compiles
bspatch as a static binary and installs it in recovery so it can be used
by update_engine_sideload.

Bug: 27178350
TEST=`mmma external/bsdiff` builds the recovery static file.

(cherry picked from commit 4bbeb1a1)

Change-Id: I25bd1925b7b04434542a29cd23c2542607b46362