title: Android trust ADB host (RSA fingerprint) without USB connection
body: <p>We are trying to automate our deployment of built android apps to test devices. These range over owned as well as leased devices - which is why we are barred from rooting or flashing.
  We have multiple build agents able to deploy. We are using ADB over TCP to deal with the deployment because of that.</p>
  
  <p>Readying new devices for app deployment is a big hassle, as we have to connect each device to every build agent (and dev machine) at least once, just to be able to confirm ADB's "trust this device" dialog. We also have some devices that do not have builtin displays and input hardware, for which this is a lot of roundabout work.</p>
  
  <p><strong>Is there a way to:</strong></p>
  
  <p>Connect <em>BuildAgentA</em> to the <em>DeviceA</em> (with USB) and somehow share the trusted adb RSA fingerprints for <em>BuildAgentB</em>&amp;<em>C</em> without having to connect the DeviceA to these build agents at all?
  So that afterwards, with adb over TCP enabled, we can simply connect and deploy from BuildAgentB to DeviceA.</p>
  
  <p><strong>Limitations:</strong></p>
  
  <ul>
  <li>We are not able or allowed to root the devices</li>
  <li>We are not able or allowed to flash the devices</li>
  </ul>