Initial skeletal implementation of the PrincipalService. Also, use the Login()/GetUserBlessing()

examples/bank_app/BUILD.gn

Index: examples/bank_app/BUILD.gn
diff --git a/examples/echo/BUILD.gn b/examples/bank_app/BUILD.gn
similarity index 66%
copy from examples/echo/BUILD.gn
copy to examples/bank_app/BUILD.gn
index 51038f69e8071427d4d6db8ea038247c791c600a..ec59eb2ed80916cd9844df4f76ae61dd9f19c568 100644
--- a/examples/echo/BUILD.gn
+++ b/examples/bank_app/BUILD.gn
@@ -5,47 +5,48 @@
 import("//mojo/public/mojo_application.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
-group("echo") {
+group("bank_app") {
   deps = [
-    ":client",
-    ":server",
+    ":customer",
+    ":bank",
   ]
 }
 
-mojo_native_application("client") {
-  output_name = "echo_client"
+mojo_native_application("customer") {
+  output_name = "customer"
 
   deps = [
     ":bindings",
-    "//base",
     "//mojo/public/cpp/application:standalone",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/utility",
+    "//mojo/services/vanadium/security/public/interfaces",
   ]
 
   sources = [
-    "echo_client.cc",
+    "customer.cc",
   ]
 }
 
-mojo_native_application("server") {
-  output_name = "echo_server"
+mojo_native_application("bank") {
+  output_name = "bank"
 
   deps = [
     ":bindings",
+    "//mojo/common",
     "//mojo/public/cpp/application:standalone",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/utility",
-    "//mojo/common",
+    "//mojo/services/vanadium/security/public/interfaces",
   ]
 
   sources = [
-    "echo_server.cc",
+    "bank.cc",
   ]
 }
 
 mojom("bindings") {
   sources = [
-    "echo.mojom",
+    "bank.mojom",
   ]
 }