Android Manifest file
If you want to build an Android app requires android manifest file.
Unity makes this file automatically by player settings when building android app.
Modify Android Manifest file
You need to modify Android manifest file because CommBluetooth use android bluetooth.
Special Path for Android Manifest file
If you want that Unity build android app using modified Android Manifest file, you should put the modified Android Manifest file to the special path.
The special path is 'Assets/Plugins/Android'.
(If this path does not exist , you must create this folder)
If you have no Android Manifest file
Don't worry, you can find Android manifest file at 'Assets/ARDUnity/Plugins/Android'.
Copy 'AndroidManifest' from 'Assets/ARDUnity/Plugins/Android' to 'Assets/Plugins/Android'.
If you already have Android Manifest file
You must add the following information to use Bluetooth in Android manifest file.
<uses-permission android:name="android.permission.BLUETOOTH"/>
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
<uses-feature android:name="android.hardware.bluetooth" android:required="true"/>
<uses-feature android:name="android.hardware.bluetooth_le" android:required="false"/>