[MM-44056] Make Calls plugin's state on Cloud controllable by feature flag (#20161)

* Make Calls plugin's state on Cloud controllable by feature flag

* Prepackage Calls v0.4.9 (#20148)

* Update app/plugin.go

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>

* Update app/plugin_install.go

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>

* Bump Calls version to latest

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/utils.go

@@ -16,6 +16,7 @@ import (
 	"net/http"
 	"net/mail"
 	"net/url"
+	"os"
 	"regexp"
 	"sort"
 	"strings"
@@ -691,3 +692,7 @@ func filterBlocklist(r rune) rune {
 
 	return r
 }
+
+func IsCloud() bool {
+	return os.Getenv("MM_CLOUD_INSTALLATION_ID") != ""
+}