Always run asan ckati on the build servers

We're seeing some rare crashes that appear to be stack overflows. To get
better debugging, use the asan version of ckati when 'dist' is
specified.

Bug: 36182021
Test: m -j
Test: m -j dist
Test: make -j dist (w/o lunch)
Change-Id: Ic3a5590974bfd718bf1929355d344b5933ac1d4f
diff --git a/ui/build/kati.go b/ui/build/kati.go
index f29d0c1..972b559 100644
--- a/ui/build/kati.go
+++ b/ui/build/kati.go
@@ -100,6 +100,9 @@
 	}
 	cmd.Stderr = cmd.Stdout
 
+	// Kati leaks memory, so ensure leak detection is turned off
+	cmd.Environment.Set("ASAN_OPTIONS", "detect_leaks=0")
+
 	cmd.StartOrFatal()
 	katiRewriteOutput(ctx, pipe)
 	cmd.WaitOrFatal()