[openweave-core] Disable security test mode

The test mode flag in openweave-core controls whether a well-known ECDH
key is used for CASE sessions, which isn't required right now and could
be added by developers in local checkouts. Removing it for the default
build to avoid running in test mode.

Bug: 46259
Test: Verified that build is silent and weavestack tests pass.
Change-Id: I56ea7331834fb30bf4785668d5f2c8c9ba7502ca
diff --git a/build/config/fuchsia/WeaveProjectConfig.h b/build/config/fuchsia/WeaveProjectConfig.h
index b368bb1..8971bc2 100644
--- a/build/config/fuchsia/WeaveProjectConfig.h
+++ b/build/config/fuchsia/WeaveProjectConfig.h
@@ -49,7 +49,7 @@
 // properly when WEAVE_CONFIG_RNG_IMPLEMENTATION_NESTDRBG is enabled.
 #define WEAVE_CONFIG_DEV_RANDOM_DRBG_SEED 1
 
-#define WEAVE_CONFIG_SECURITY_TEST_MODE 1
+#define WEAVE_CONFIG_SECURITY_TEST_MODE 0
 
 #define WDM_ENFORCE_EXPIRY_TIME 1