FTL: Add thread safety helpers

Bug: 185536303
Test: ftl_test
Change-Id: I0f0550d0608a11b137741cd94248b5bc533a0304
diff --git a/libs/ftl/Android.bp b/libs/ftl/Android.bp
index bc2eb23..97b522a 100644
--- a/libs/ftl/Android.bp
+++ b/libs/ftl/Android.bp
@@ -18,6 +18,7 @@
         "cast_test.cpp",
         "concat_test.cpp",
         "enum_test.cpp",
+        "fake_guard_test.cpp",
         "future_test.cpp",
         "small_map_test.cpp",
         "small_vector_test.cpp",
@@ -29,6 +30,7 @@
         "-Werror",
         "-Wextra",
         "-Wpedantic",
+        "-Wthread-safety",
     ],
 
     header_libs: [