binder: Notify iface add/remove to binder

Notify |BinderManager| about any new iface addition/removal from
|wpa_supplicant| core.
|Iface| objects are stateless in the sense that they only
hold the name of the iface it controls. Every RPC call through the iface object
will first invoke |wpa_supplicant_get_iface| to ensure that the iface still
exists in the wpa_supplicant core.

While there,
1. Add some debug logs in binder.cpp.
2. Change C style comments to c++ style.
3. Add @utf8incpp annotation at the interface level in all the aidl files.

BUG: 29998764
TEST: Tested using the |gTest| integration tests. Will upload these under
|wificond|

Change-Id: If69bfaece7a6f69640fe8cbf90d1006a88aef8af
Signed-off-by: Roshan Pius <rpius@google.com>
diff --git a/wpa_supplicant/binder/binder.cpp b/wpa_supplicant/binder/binder.cpp
index 750e878..eb6006c 100644
--- a/wpa_supplicant/binder/binder.cpp
+++ b/wpa_supplicant/binder/binder.cpp
@@ -41,12 +41,16 @@
 		return NULL;
 	priv->global = global;
 
+	wpa_printf(MSG_DEBUG, "Initing binder control");
+
 	android::ProcessState::self()->setThreadPoolMaxThreadCount(0);
 	android::IPCThreadState::self()->disableBackgroundScheduling(true);
 	android::IPCThreadState::self()->setupPolling(&priv->binder_fd);
-	wpa_printf(MSG_INFO, "Process binder events on FD %d", priv->binder_fd);
 	if (priv->binder_fd < 0)
 		goto err;
+
+	wpa_printf(
+	    MSG_INFO, "Processing binder events on FD %d", priv->binder_fd);
 	/* Look for read events from the binder socket in the eloop. */
 	if (eloop_register_read_sock(
 		priv->binder_fd, wpas_binder_sock_handler, global, priv) < 0)
@@ -72,6 +76,8 @@
 	if (!priv)
 		return;
 
+	wpa_printf(MSG_DEBUG, "Deiniting binder control");
+
 	wpa_supplicant_binder::BinderManager::destroyInstance();
 	eloop_unregister_read_sock(priv->binder_fd);
 	android::IPCThreadState::shutdown();
@@ -82,6 +88,10 @@
 	if (!wpa_s->global->binder)
 		return 1;
 
+	wpa_printf(
+	    MSG_DEBUG, "Registering interface to binder control: %s",
+	    wpa_s->ifname);
+
 	wpa_supplicant_binder::BinderManager *binder_manager =
 	    wpa_supplicant_binder::BinderManager::getInstance();
 	if (!binder_manager)
@@ -95,6 +105,10 @@
 	if (!wpa_s->global->binder)
 		return 1;
 
+	wpa_printf(
+	    MSG_DEBUG, "Deregistering interface from binder control: %s",
+	    wpa_s->ifname);
+
 	wpa_supplicant_binder::BinderManager *binder_manager =
 	    wpa_supplicant_binder::BinderManager::getInstance();
 	if (!binder_manager)