Change expected rmw GID array size to 16 bytes

The size changed from 24 to 16 bytes in ros2/rmw#345. The same size is
defined in `tracetools`, and it was never updated.

In practice, reading 24-16=8 random extra bytes didn't change much,
since nothing is currently relying on the GID values, at least not
relying on getting the same GID for the same object from two different
systems, because it doesn't work with `rmw_cyclonedds`, see
ros2/rmw_cyclonedds#377.

Signed-off-by: Christophe Bedard <christophe.bedard@apex.ai>

test_tracetools/test/test_generic_subscription.py

@@ -66,7 +66,7 @@ def test_all(self):
 
         for event in rmw_sub_init_events:
             self.assertValidHandle(event, ['rmw_subscription_handle'])
-            self.assertValidStaticArray(event, 'gid', int, 24)
+            self.assertValidStaticArray(event, 'gid', int, 16)
         for event in rcl_sub_init_events:
             self.assertValidHandle(
                 event,

test_tracetools/test/test_publisher.py

@@ -47,7 +47,7 @@ def test_all(self):
         rmw_pub_init_events = self.get_events_with_name(tp.rmw_publisher_init)
         for event in rmw_pub_init_events:
             self.assertValidHandle(event, ['rmw_publisher_handle'])
-            self.assertValidStaticArray(event, 'gid', int, 24)
+            self.assertValidStaticArray(event, 'gid', int, 16)
         pub_init_events = self.get_events_with_name(tp.rcl_publisher_init)
         for event in pub_init_events:
             self.assertValidHandle(

test_tracetools/test/test_subscription.py

@@ -65,7 +65,7 @@ def test_all(self):
 
         for event in rmw_sub_init_events:
             self.assertValidHandle(event, ['rmw_subscription_handle'])
-            self.assertValidStaticArray(event, 'gid', int, 24)
+            self.assertValidStaticArray(event, 'gid', int, 16)
         for event in rcl_sub_init_events:
             self.assertValidHandle(
                 event,

tracetools/include/tracetools/tp_call.h

@@ -35,7 +35,7 @@
 #include "tracetools/version.h"
 
 /// See RMW_GID_STORAGE_SIZE in rmw.
-#define TRACETOOLS_GID_STORAGE_SIZE 24u
+#define TRACETOOLS_GID_STORAGE_SIZE 16u
 
 #ifdef __clang__
 # pragma clang diagnostic push