libbinder: attachObject APIs work with threads

These APIs now return values so that they can be used in a
multi-threaded environment without needing additional locking.

Bug: 192023359
Test: binderLibTest
Change-Id: Idc9054bde869a57c2cb5142963aae362674ce0c0
diff --git a/libs/binder/tests/Android.bp b/libs/binder/tests/Android.bp
index 8faa3b8..565f88e 100644
--- a/libs/binder/tests/Android.bp
+++ b/libs/binder/tests/Android.bp
@@ -84,7 +84,7 @@
             enabled: false,
         },
     },
-    srcs: ["binderParcelUnitTest.cpp"],
+    srcs: ["binderParcelUnitTest.cpp", "binderBinderUnitTest.cpp"],
     shared_libs: [
         "libbinder",
         "libutils",