BleAdvertisements sample code need be updated for Android 8 and above

[basin0809]

For people who need run BleAdvertisements sample on Android 8 or above, below changes are necessary:

1. add android.permission.ACCESS_FINE_LOCATION to manifest, and ask run time permission for it.
2. add android.permission.FOREGROUND_SERVICE to manifest, otherwise app would crash once it starts advertising service.
3. Create a notification channel for the advertising service, otherwise startForground() will complain bad notification and crash the app.

[Y3hu]

Yo also have to change Notification.Builder(Context context) to Notification.Builder(Context context, String string)

Notification.Builder documentation

[isaidamier]

We have provided a Kotlin version that is up to date: https://github.com/android/connectivity-samples/tree/main/BluetoothAdvertisementsKotlin