Don't check the return type in the builder.

The verifier will not complain about dead code. For the compiler,
it is benign.

bug:21863767

(cherry picked from commit 69505f86a1a653bf86c1f2b423b3e0605137d5d1)

Change-Id: I2bc7888b39c91862c6dade130eccdf92f19b3f6f
4 files changed