FTL: Add Optional<T>::transform

Bug: 185536303
Test: ftl_test
Change-Id: If4cb9894c615499af04bb9793d9f900485e18fe2
diff --git a/libs/ftl/Android.bp b/libs/ftl/Android.bp
index c010a2e..8f89e7d 100644
--- a/libs/ftl/Android.bp
+++ b/libs/ftl/Android.bp
@@ -20,6 +20,7 @@
         "fake_guard_test.cpp",
         "flags_test.cpp",
         "future_test.cpp",
+        "optional_test.cpp",
         "small_map_test.cpp",
         "small_vector_test.cpp",
         "static_vector_test.cpp",