Fix Global Actions animations, and use old power menu when panel is disabled.

Also tweak feature flags setup to use old flag as a force option for debugging.

Test: Automated tests pass. Long-press power menu without plugin installed from different device orientations -- menu should animate in from the closest screen edge in all orientations and rotate correctly when device is rotated. Repeat after enabling the settings_global_actions_force_grid_enabled option in Feature Flags to ensure the correct behavior persists when using the new grid layout.

Fixes: 126444760
Fixes: 129698948

Change-Id: I9ac387244a5904f832c5d8b6c40362c00c6a22a2