libbinder: support inheriting realtime priority

gotta go fast

Bug: 170420170
Test: atest binderLibTest
Change-Id: I2f2c6cb35ebf463d90b517e134b9ea3114764af6
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index a7d8df2..3330a2e 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -222,6 +222,9 @@
             if (local->isRequestingSid()) {
                 obj.flags |= FLAT_BINDER_FLAG_TXN_SECURITY_CTX;
             }
+            if (local->isInheritRt()) {
+                obj.flags |= FLAT_BINDER_FLAG_INHERIT_RT;
+            }
             obj.hdr.type = BINDER_TYPE_BINDER;
             obj.binder = reinterpret_cast<uintptr_t>(local->getWeakRefs());
             obj.cookie = reinterpret_cast<uintptr_t>(local);