Add new WM private API for batched setting.

This commit introduces a new private API to the window manager service.
The `setConfigurationChangeSettingsForUser()` API provides a flexible
and extensible mechanism for applying batched setting that trigger
configuration changes.

It consolidates configuration changes when multiple settings are
modified together, preventing activity restarts due to intermediate
configuration changes.

Bug: 356738240
Test: atest FrameworksCoreTests:ConfigurationChangeSettingTest
Test: atest WmTests:WindowManagerServiceTests
Flag: com.android.window.flags.condense_configuration_change_for_simple_mode
Change-Id: I1b21808d54ba6d17b6464f84ac5920d50e96332d