Native: tried calling BLE.startScan, but the BLE plugin is not installed.

**Description:**

I'm using Ionic cordova [BLE plugin](https://ionicframework.com/docs/native/ble). When I run

> ionic cordova run android

Everything is fine. However when I run

> ionic serve --devapp

The first time it works. When I restart DevApp application. It tells me that the plugin is not installed although it's well installed and it works fine.

**Steps to Reproduce:**

**Output:**

> [INFO] DevApp connection established from SM-G965F
>
> [ng] [console.log]: "Angular is running in the development mode. Call enableProdMode() to enable the production mode."
> [ng] [console.warn]: "Native: tried calling BLE.startScan, but the BLE plugin is not installed."
> [ng] [console.warn]: "Install the BLE plugin: 'ionic cordova plugin add cordova-plugin-ble-central'"
> [ng] [console.warn]: "Native: tried calling BLE.stopScan, but the BLE plugin is not installed."
> [ng] [console.warn]: "Install the BLE plugin: 'ionic cordova plugin add cordova-plugin-ble-central'"
> [ng] [console.error]: "ERROR" "plugin_not_installed"
> [ng] [console.info]: "[WDS] Live Reloading enabled."
> [ng] [console.log]: "calling _sync"
> [ng] [console.log]: "calling _reload"
> [ng] [console.log]: "done _reloading"
> [ng] [console.log]: "Ionic Native: deviceready event fired after 2673 ms"

**My `ionic info`:**

```
Ionic:

Ionic CLI : 5.4.10 (/usr/local/lib/node_modules/ionic)
Ionic Framework : @ionic/angular 4.11.5
@angular-devkit/build-angular : 0.801.3
@angular-devkit/schematics : 8.1.3
@angular/cli : 8.1.3
@ionic/angular-toolkit : 2.1.1

Cordova:

Cordova CLI : 9.0.0 (cordova-lib@9.0.1)
Cordova Platforms : android 8.1.0
Cordova Plugins : cordova-plugin-ionic-keyboard 2.2.0, cordova-plugin-ionic-webview 4.1.3, (and 5 other plugins)

Utility:

cordova-res : 0.8.1
native-run : 0.3.0

System:

ios-deploy : 1.9.4
NodeJS : v12.13.1 (/usr/local/bin/node)
npm : 6.12.1
OS : macOS Catalina
```

**Other Information:**

The report concerns ionic serve --devapp with the Cordova BLE plugin on Android; start by tracing the DevApp reload path after the first successful run. Reproduce the restart sequence and use the logged plugin_not_installed warnings as the failure signal; done means the BLE plugin remains available after restarting DevApp.

Rédigé par le modèle d'indexation à partir du texte de l'issue.