AWS upgrade role entries (#7025)

* upgrade aws roles

* test upgrade aws roles

* Initialize aws credential backend at mount time

* add a TODO

* create end-to-end test for builtin/credential/aws

* fix bug in initializer

* improve comments

* add Initialize() to logical.Backend

* use Initialize() in Core.enableCredentialInternal()

* use InitializeRequest to call Initialize()

* improve unit testing for framework.Backend

* call logical.Backend.Initialize() from all of the places that it needs to be called.

* implement backend.proto changes for logical.Backend.Initialize()

* persist current role storage version when upgrading aws roles

* format comments correctly

* improve comments

* use postUnseal funcs to initialize backends

* simplify test suite

* improve test suite

* simplify logic in aws role upgrade

* simplify aws credential initialization logic

* simplify logic in aws role upgrade

* use the core's activeContext for initialization

* refactor builtin/plugin/Backend

* use a goroutine to upgrade the aws roles

* misc improvements and cleanup

* do not run AWS role upgrade on DR Secondary

* always call logical.Backend.Initialize() when loading a plugin.

* improve comments

* on standbys and DR secondaries we do not want to run any kind of upgrade logic

* fix awsVersion struct

* clarify aws version upgrade

* make the upgrade logic for aws auth more explicit

* aws upgrade is now called from a switch

* fix fallthrough bug

* simplify logic

* simplify logic

* rename things

* introduce currentAwsVersion const to track aws version

* improve comments

* rearrange things once more

* conglomerate things into one function

* stub out aws auth initialize e2e test

* improve aws auth initialize e2e test

* finish aws auth initialize e2e test

* tinker with aws auth initialize e2e test

* tinker with aws auth initialize e2e test

* tinker with aws auth initialize e2e test

* fix typo in test suite

* simplify logic a tad

* rearrange assignment

* Fix a few lifecycle related issues in #7025 (#7075)

* Fix panic when plugin fails to load

sdk/framework/backend_test.go

@@ -642,3 +642,18 @@ func TestFieldSchemaDefaultOrZero(t *testing.T) {
 		}
 	}
 }
+
+func TestInitializeBackend(t *testing.T) {
+
+	var inited bool
+	backend := &Backend{InitializeFunc: func(context.Context, *logical.InitializationRequest) error {
+		inited = true
+		return nil
+	}}
+
+	backend.Initialize(nil, &logical.InitializationRequest{Storage: nil})
+
+	if !inited {
+		t.Fatal("backend should be open")
+	}
+}