Update the recovery files under SYSTEM/ if recovery patch is rebuilt

If we pass "rebuild_recovery" to add_img_to_target_files, the recovery
patch is rebuilt. But related files under SYSTEM/ (e.g.
SYSTEM/recovery-from-boot.p && SYSTEM/bin/install-recovery.sh) are not
updated.

This may cause a mismatch between system.img and SYSTEM/, and
may lead to a failure in validate_target_files.py.

Bug: 62096364
Test: Rebuild the system image in the TF and observe the recovery files
under SYSTEM/ get updated.

Change-Id: I7d679a612a86d02cf2eff81d1d120c0067138ed9