Expand notif activity starter lifetime extension

Another animation is played while launching the intent for a
notification. This CL moves the onFinishLaunchNotifActivity invocation
until after that animation has ended (or after checking that it won't be
played).

Fixes: 220725343
Test: 1. Install Notify.apk (go/notify-apk)
      2. In the Notify app: Check off Delayed 5000 and Auto Cancel
      3. Click "Add" and spam click "Update" (5-10 times should suffice)
      4. Immediately tap the Notify heads up notification when it gets
         posted
      Observe: no crashing
Change-Id: I13312b4c42b4147fb061db617302cde4b45829ff