Reducing Popups: remove plugin transfer notification (#7910)

This reverts commit c537494.

Author: LeFrosch

base/src/META-INF/blaze-base.xml

@@ -441,9 +441,6 @@
     <registryKey defaultValue="false"
                  description="Mark execroot as dirty before refresh after sync"
                  key="bazel.sync.mark.dirty"/>
-
-    <notificationGroup id="com.google.idea.blaze.base.ide.TransferNotificationActivity" displayType="BALLOON"/>
-    <postStartupActivity implementation="com.google.idea.blaze.base.ide.TransferNotificationActivity"/>
   </extensions>
 
   <extensions defaultExtensionNs="com.intellij">