Make dynamic endpoint lifetime more similar to that of fixed endpoints.

Specific changes:

1) Ensure that dynamic endpoints land in initializeEndpoint (via
   emberAfEndpointEnableDisable) like fixed ones do (via emAfCallInits).

2) Ensure that clearing an dynamic endpoint properly disables it.
   This makes sure we call emberAfDeactivateClusterTick as needed and
   we can add other cleanup inside emberAfEndpointEnableDisable as it
   becomes useful.

3) Move the emberAfPluginDescriptorServerInitCallback calls for
   dymanic endpoints to the one choke-point in
   emberAfEndpointEnableDisable.  This also fixes a pre-existing issue
   where disabling a fixed endpoint would not correctly update the
   descriptor bits.

4) In descriptor, check for enabled state before trying to actually
   touch the endpoint's data, not after we have tried to touch some of
   it.

src/app/clusters/descriptor/descriptor.cpp

@@ -131,13 +131,13 @@ void emberAfPluginDescriptorServerInitCallback(void)
 
     for (uint16_t index = 0; index < emberAfEndpointCount(); index++)
     {
-        EndpointId endpoint = emberAfEndpointFromIndex(index);
-        if (!emberAfContainsCluster(endpoint, Descriptor::Id))
+        if (!emberAfEndpointIndexIsEnabled(index))
         {
             continue;
         }
 
-        if (!emberAfEndpointIndexIsEnabled(index))
+        EndpointId endpoint = emberAfEndpointFromIndex(index);
+        if (!emberAfContainsCluster(endpoint, Descriptor::Id))
         {
             continue;
         }

src/app/util/attribute-storage.cpp

@@ -148,6 +148,8 @@ void emberAfEndpointConfigure(void)
 #ifdef DYNAMIC_ENDPOINT_COUNT
     if (MAX_ENDPOINT_COUNT > FIXED_ENDPOINT_COUNT)
     {
+        // This is assuming that EMBER_AF_ENDPOINT_DISABLED is 0
+        static_assert(EMBER_AF_ENDPOINT_DISABLED == 0, "We are creating enabled dynamic endpoints!");
         memset(&emAfEndpoints[FIXED_ENDPOINT_COUNT], 0,
                sizeof(EmberAfDefinedEndpoint) * (MAX_ENDPOINT_COUNT - FIXED_ENDPOINT_COUNT));
     }
@@ -196,15 +198,14 @@ EmberAfStatus emberAfSetDynamicEndpoint(uint16_t index, EndpointId id, EmberAfEn
     emAfEndpoints[index].deviceVersion = deviceVersion;
     emAfEndpoints[index].endpointType  = ep;
     emAfEndpoints[index].networkIndex  = 0;
-    emAfEndpoints[index].bitmask       = EMBER_AF_ENDPOINT_ENABLED;
+    // Start the endpoint off as disabled.
+    emAfEndpoints[index].bitmask       = EMBER_AF_ENDPOINT_DISABLED;
 
     emberAfSetDynamicEndpointCount(MAX_ENDPOINT_COUNT - FIXED_ENDPOINT_COUNT);
-    emberAfSetDeviceEnabled(id, true);
 
-#ifdef ZCL_USING_DESCRIPTOR_CLUSTER_SERVER
-    // Rebuild descriptor attributes on all endpoints
-    emberAfPluginDescriptorServerInitCallback();
-#endif
+    // Now enable the endpoint.
+    emberAfEndpointEnableDisable(id, true);
+    emberAfSetDeviceEnabled(id, true);
 
     return EMBER_ZCL_STATUS_SUCCESS;
 }
@@ -221,14 +222,9 @@ EndpointId emberAfClearDynamicEndpoint(uint16_t index)
         if (ep)
         {
             emberAfSetDeviceEnabled(ep, false);
+            emberAfEndpointEnableDisable(ep, false);
             emAfEndpoints[index].endpoint = 0;
-            emAfEndpoints[index].bitmask  = 0;
         }
-
-#ifdef ZCL_USING_DESCRIPTOR_CLUSTER_SERVER
-        // Rebuild descriptor attributes on all endpoints
-        emberAfPluginDescriptorServerInitCallback();
-#endif
     }
 
     return ep;
@@ -981,6 +977,11 @@ bool emberAfEndpointEnableDisable(EndpointId endpoint, bool enable)
                     (cluster->mask & CLUSTER_MASK_CLIENT ? EMBER_AF_CLIENT_CLUSTER_TICK : EMBER_AF_SERVER_CLUSTER_TICK));
             }
         }
+
+#ifdef ZCL_USING_DESCRIPTOR_CLUSTER_SERVER
+        // Rebuild descriptor attributes on all endpoints
+        emberAfPluginDescriptorServerInitCallback();
+#endif
     }
 
     return true;