Honor TARGET_NO_RECOVERY flag.

Don't generate recovery.img when calling 'make dist' if
TARGET_NO_RECOVERY is set. The build system passes the flag to the
packaging script which then generates recovery.img conditionally.

Bug: 25329471
Change-Id: Ia7f08943834ee39e781d7e9b5beb1b31d95a73d9
(cherry picked from commit db45efa647)

tools/releasetools/ota_from_target_files.py

@@ -1620,6 +1620,10 @@ def main(argv):
   if OPTIONS.device_specific is not None:
     OPTIONS.device_specific = os.path.abspath(OPTIONS.device_specific)
 
+  if OPTIONS.info_dict.get("no_recovery") == "true":
+    raise common.ExternalError(
+        "--- target build has specified no recovery ---")
+
   while True:
 
     if OPTIONS.no_signing: