Change the flag of magnification settings to TYPE_NAVIGATION_BAR_PANE

Change the flag of magnification settings panel to
TYPE_NAVIGATION_BAR_PANE to allow users to interact with the panel
through accessibility services.

Bug: 266499977
Test: manually - attach videos to the bug
Test: atest MagnificationSettingsControllerTest
WindowMagnificationSettingsTest

Change-Id: I58069c7f1d81487853cc7555508beb2d1aa2b2e8