Make getCallingUid/Pid const.

Change-Id: I1853b21eaa45d85274189dfd72f73fec48d0d6b7
diff --git a/include/binder/IPCThreadState.h b/include/binder/IPCThreadState.h
index ad0daee..5bc123e 100644
--- a/include/binder/IPCThreadState.h
+++ b/include/binder/IPCThreadState.h
@@ -39,8 +39,8 @@
             
             status_t            clearLastError();
 
-            int                 getCallingPid();
-            int                 getCallingUid();
+            int                 getCallingPid() const;
+            int                 getCallingUid() const;
 
             void                setStrictModePolicy(int32_t policy);
             int32_t             getStrictModePolicy() const;