The Android operating system provides its own means of managing VPN connections and invoking similar protections to the killswitch.
First open your Android Settings interface:
Then navigate to the Network & internet settings:
Next, expand the Advanced options:
Then select VPN:
Tap the settings button next to the PIA VPN option:
This menu will allow you to turn on Always-on VPN, which aims to connect the VPN whenever possible:
When Always-on VPN is enabled you will gain access to Block connections without VPN which will prevent internet traffic if the VPN is not connected: