Allow a list of packages to be whitelisted to auto-bubble

If the notification has metadata (regardless if from experiment or not)
and that package has been whitelisted, then it will automatically bubble.

Supports multiple packages as long as it's in a comma separated list.

Test: manual:

1) set some packages to be whitelisted:
adb shell settings put secure whitelisted_auto_bubble_apps com.instagram.android,com.google.android.calendar,com.google.android.apps.photos

2) enable message bubbles / any bubbles:
adb shell settings put secure allow_any_notifs_to_bubble 1

3) get a notification that has enough info to bubble from one of those apps
=> it autobubbles

4) get an update to that notification
=> it goes to the bubble

Bug: 145763712
Change-Id: Ic2c26968dcb345e088044a73b30fef82d65552ae