Move feature-level Bubble setting into developer options; default to off

Functionality:
* Moves feature-level setting into developer settings (apps section)
* Adds bubbles in developer options under "apps" section
* Configures the app-specific bubble toggle in notifications settings
  to be hidden / shown based on the developer setting
* Configures the channel-specific bubble toggle in notification channel
  settings to be hidden / shown based on the developer setting

Tests:
* Anything that might be assuming that it's globally enabled now has
  a bit to enable it globally in that test
* There is a logic change now where the app-level setting would be available
  even if off globally, now that is not true -- if it's off globally the
  app-level is no longer available
* Adds tests for the developer setting

Test: make -j40 RunSettingsRoboTests ROBOTEST_FILTER="Bubble"
Bug: 131845765
Change-Id: I5f6bf74e5ada3fc023571825cca10d7bddc60e6e