Emit progress events on APK installation.

lib/roles/device/plugins/install.js

@@ -18,9 +18,25 @@ module.exports = syrup.serial()
       log.info('Installing "%s"', message.url)
       var source = new stream.Readable().wrap(request(message.url))
       var seq = 0
+      push.send([
+        channel
+      , wireutil.envelope(new wire.TransactionProgressMessage(
+          options.serial
+        , seq++
+        , 'installing'
+        ))
+      ])
       adb.install(options.serial, source)
         .then(function() {
           if (message.launchActivity) {
+            push.send([
+              channel
+            , wireutil.envelope(new wire.TransactionProgressMessage(
+                options.serial
+              , seq++
+              , 'launching activity'
+              ))
+            ])
             log.info(
               'Launching activity with action "%s" on component "%s"'
             , message.launchActivity.action