FTL: Pull Flags into namespace

Bug: 185536303
Test: Build
Change-Id: Ia9aafc78565414815dfc14732ce85b06fa96e17b
diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index 14d8f98..fa36d9c 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -34,12 +34,13 @@
 using namespace std::chrono_literals;
 using namespace std::placeholders;
 
-using namespace android::flag_operators;
 using testing::_;
 using testing::Invoke;
 
 namespace android {
 
+using namespace ftl::flag_operators;
+
 namespace {
 
 constexpr PhysicalDisplayId INTERNAL_DISPLAY_ID = PhysicalDisplayId::fromPort(111u);