diagnose-build-failure.sh skipping output for individual gradle runs

in case we want to save all of its output somewhere and not have too much output

Bug: 187822154
Change-Id: Ic7a5d35003957d1027b1261670b3d33c5610c33e
diff --git a/development/diagnose-build-failure/diagnose-build-failure.sh b/development/diagnose-build-failure/diagnose-build-failure.sh
index d86e967..a6d2279 100755
--- a/development/diagnose-build-failure/diagnose-build-failure.sh
+++ b/development/diagnose-build-failure/diagnose-build-failure.sh
@@ -139,7 +139,7 @@
   cleanupCommand="$scriptPath/impl/backup-state.sh \$testDir $workingDir --move >/dev/null"
 
   fullFiltererCommand="$setupCommand
-if $buildCommand; then
+if $buildCommand >/dev/null 2>/dev/null; then
   $cleanupCommand
   exit $successStatus
 else