C2VdaBqBlockPool: avoid unnecessary function call at surface switch

This CL changes the order of the function call at configuring producer
to avoid unnecessary call when any error occurs or the producer is not
changed.

Bug: 160110407
Test: android.media.cts.MediaCodecPlayerTest#testPlaybackSwitchViews

Change-Id: I194f929ab7dbdaa10ab55dd3a11ca4a1c9a0d40a