Increase flush timeout in heap_profile script.

TBR=rsavitski

Change-Id: I80f8637c04c71d6b64db96405a72a8bc7927038a

tools/heap_profile

diff --git a/tools/heap_profile b/tools/heap_profile
index 942c807..91f7ee5 100755
--- a/tools/heap_profile
+++ b/tools/heap_profile
@@ -97,6 +97,7 @@
 }}
 
 duration_ms: {duration}
+flush_timeout_ms: 30000
 '''
 
 CONTINUOUS_DUMP = """