Add a compile time flag to only upload crash symbols for official builds

blimp/engine/app/blimp_engine_crash_reporter_client.cc

Index: blimp/engine/app/blimp_engine_crash_reporter_client.cc
diff --git a/blimp/engine/app/blimp_engine_crash_reporter_client.cc b/blimp/engine/app/blimp_engine_crash_reporter_client.cc
index e9b026c220ea0965d6dd9706c888d972724c0686..9bc993b17c9161dd11e0e76bd356bedc74c443de 100644
--- a/blimp/engine/app/blimp_engine_crash_reporter_client.cc
+++ b/blimp/engine/app/blimp_engine_crash_reporter_client.cc
@@ -45,8 +45,12 @@ bool BlimpEngineCrashReporterClient::IsRunningUnattended() {
 }
 
 bool BlimpEngineCrashReporterClient::GetCollectStatsConsent() {
-  // Always collect Blimp engine crash reports.
+  // Always collect Blimp engine crash reports on official builds.
+#ifdef OFFICIAL_BUILD
   return true;
+#else
+  return false;
+#endif  // OFFICIAL_BUILD
 }
 
 bool BlimpEngineCrashReporterClient::EnableBreakpadForProcess(