Enable object-size sanitizer for C++

This was previously disabled due to a bug in libc++'s __tree implementation. That bug has been fixed, so we can now enable this sanitizer.

Change-Id: Ibbdfbe843aa02ef31d2a10b0c6a87500b7f60b42
Test: presubmit
diff --git a/android/config.go b/android/config.go
index b682c2e..68743ac 100644
--- a/android/config.go
+++ b/android/config.go
@@ -238,6 +238,11 @@
 	return c.config.productVariables.ReleaseAconfigFlagDefaultPermission
 }
 
+// Enable object size sanitizer
+func (c Config) ReleaseBuildObjectSizeSanitizer() bool {
+	return c.config.productVariables.GetBuildFlagBool("RELEASE_BUILD_OBJECT_SIZE_SANITIZER")
+}
+
 // The flag indicating behavior for the tree wrt building modules or using prebuilts
 // derived from RELEASE_DEFAULT_MODULE_BUILD_FROM_SOURCE
 func (c Config) ReleaseDefaultModuleBuildFromSource() bool {