sign_target_files_apks: Relax ro.build.description requirements

Some OEMs, namely OnePlus don't use AOSP compliant build description.
Making sure that the last piece ends with -keys is more than enough.

Change-Id: Iefa3c408a3fdda0b63db257befb8ba2d36793293

tools/releasetools/sign_target_files_apks.py

@@ -799,7 +799,7 @@ def RewriteProps(data):
         value = "/".join(pieces)
       elif key == "ro.build.description":
         pieces = value.split(" ")
-        assert len(pieces) == 5
+        assert pieces[-1].endswith("-keys")
         pieces[-1] = EditTags(pieces[-1])
         value = " ".join(pieces)
       elif key.startswith("ro.") and key.endswith(".build.tags"):